TL;DR : Jump to the last paragraph for the conclusion and practical cases. But don't forget to breathe, skipping things can be a sign of having a constant turning around and upon you ♪. Or that I'm boring, as well 🦋.
I like to take things the other way round, so here's the path I take:
Let's look at the core question in the question's body : Should you ask people to avoid answering bad questions? It goes beyond what people think in reaction to the question, and it's easy to miss a few things.
It's simple to understand, but it's harder to feel it, so let's get back to basics! From the help center, the section "how do I write a good answer":
Answer well-asked questions
Not all questions can or should be answered here. Save yourself some frustration and avoid trying to answer questions which [are unclear, opinion-based, duplicates, need focus, off-topic].
This is an explicit, official ruling, and so should be respected. To be followed, it needs to be known and recalled from time to time. As this recurring nice comment shows, having a single paragraph lost in a help center with > 20 sections doesn't seem to be enough:
Welcome to Wordbuilding SE! You may want to take the tour and peruse the help center, in order to become better acquainted with the goals and expectations of this site.
Welcoming and ack-knowledging, by AlexP (though there are many, many others examples reminding people to reach for the help-center).
So, yes, to ensure people follow this rule, we should remind people to not answer badly written questions. Or should we?
Epic battle of viewpoints!
A point that seems to stand amongst people that disagree with this previous guideline is that answerers spend some of their free time to help others, so telling them to not answer will be badly received, in all cases. It's about the same thing as yelling at the man who hands you the wrong item from a shelf you couldn't reach.
But most importantly, the issue is that one user thinks a question should be closed, while another in all honesty doesn't! It usually happens when a question is in the quality's grey area. This makes it really hard to tell answerers they did something wrong—whether it's objectively true or not—since from their point of view they didn't. They don't understand, and unless they're painting happy little accidents daily, it's very likely to lead to some confusion, if not tough resistance. All for understandable and acceptable reasons from their point of view.
I can only agree with the above points, and they have to be taken into consideration to avoid being inconsiderate towards others.
So! To help recall this rule without striking at the answerer's feeling, let's remember three things:
1. Answerers are not forced to post right now
Firstly, and really importantly, because it's needed for the other points: people are not forced to answer right now.
If there's an ongoing debate on a question you wish to answer, you can just wait a little to see where it goes. After all, closure should happen quickly! Or, if you're more invested, talk it out to make your point before answering.
I see a lot of users mentioning the reasons they're voting for a question to be closed. But, interestingly, I see much fewer people answering soon-to-become closed questions telling why they found the question's quality to be high enough to answer. As much as everybody wants as few closed questions as possible, it's not on the close-voters side to give counter-arguments to their closure reasons. At best, they can give directions to improve the question. Defending the question is a task better suited for the ones who thought it worth answering!
2. The asker's question is burdened by the answerer's action
Let's not forget the negative aspect of answering questions without taking the time to think about the question. By doing so, it often prevents further editing of the question when it gets closed. Questions whose purpose it is to help the asker. It makes it a lot harder to edit it while keeping the answer valid, and since the question has been posted, it makes it harder to post a new similar-looking one. It is especially true for newcomers who are more prone to write questions that need improvements, have a harder time improving them, and can get discouraged much more easily.
Therefore remember to whom the added weight belongs, and don't reverse the responsibility: even if the asker didn't do things as expected, it's the answerer who's taking the responsibility of answering. And as such, the Help Center quite clearly points out how not answering bad questions might:
Save yourself some frustration...
As the answerer, save yourself the frustration of getting your work invalidated or be a burden to the asker. If you took the step to help, burdening the asker is not what you want, or so I guess. It's not to follow a silly rule that makes no sense, it's to save everyone from the trouble a question's stunlock can make. It's something that can be done to help people either delete and repost their question later or reopen them, both very lengthy processes that definitely need any help to be finished faster.
3. The answerer can edit or help editing the question
In case the closure of a question is already on-going—and, most importantly, known—the answerer can and should edit the question. As per the Help Center, the same paragraph about not answering bad questions:
Don't forget that you can edit the question you're answering to improve the clarity and focus - this can reduce the chances of the question being closed or deleted.
It should be done when the question runs the risk of getting struck by the close-hammers (plural, they usually don't act alone). Ideally you do it before you answer it. However, if you went a little too fast in answering before others judged it, it's always possible to improve the question to avoid closure, or help the asker if you fear that you might alter more than they want. Pick and peck, you could use your own answer to help them keep their question open (e.g. for "Lack of details/clarity": am I right in my answer about the assumptions I made about your world? Can I add them to your question?).
It's all in the mindset that questions and answers are intertwined: you can't really correctly answer bad questions. That's the key point of good answers, you need to have a clear, well-defined target to focus it. Otherwise you're most likely to miss what the asker wants or clumsily answering that you don't know where the focus lies! Soooo... It's as simple as improving bad questions before answering.
Since you should be an expert in the domain -if not a SE veteran-, it should be easier to spot the question's weaknesses and work on them. If you don't do this, you risk finding out that your answer doesn't match the new and actual question or didn't help that much. Frustration is then ensured. And if you realize there could be an issue with the question, defend it with the asker 🛡️. Your answer is part of the question too, after all!
TL;DR people, here is your starting line!
There are many methods and reasons for an answerer to help improve a question. And, if a question is improved to be considered as fit, cozy and nice, is there ever the need to keep people from answering it 🦋?
That's the key thing here: questions are not stuck in time, they can evolve through both the asker and others! And this flips the direction we should see things: it's not about not answering bad questions, it's about not having bad questions with answers. And with their knowledge and their point of view, the answerers are in one of the best spots to give a hand at that task!
As much as you can remind people that answering bad questions can have nasty consequences, I'd advise to cooperate with answerers in improving the question, removing the need to recall that at all. If they don't understand why they should help, then remind them of the hassle they or the asker might run into—as a reason to do that, not as an action to avoid taking.
In order to do that, you have to check one or two things beforehand:
- Does this question have a debate about closure?
By debate I mean at least a comment + a close vote (if you can see it), a comment + a negative vote, or several comments (counting comment upvotes). All of these should not be yours.
- If there's an on-going debate, how many people are agreeing with the idea of a closure and how many are disagreeing? In other words, how obvious the outcome of the vote(s) to close is?
If you're the only one to think the question's not good enough to be answered, or overall it's so unclear that it should be closed, don't remind people to not answer bad questions. It would be a one-on-one opinion fight, where no-one will be the victor. Instead, wait a little until others approve your opinion or -if you're more invested- ask something like this:
I have some contradicting opinion on whether the question should be
closed or not: can you explain why you think this question
should be kept open and answered in its current state, as told in the help-center? Or can you help improve on the points which have been raised?
If there's a debate, and it's really obvious (you're far from being the only one and there's no one opposing the closure or it's already been closed), then you can remind people of the risk they're taking. It's the only time I'd recall the issues, but for the purpose of inciting on lending an hand to the question. For instance for a question which needs details or focus:
The question's currently undergoing a closure debate and it seems to lean towards a closure at the time I write this. It is generally not advised to answer a question under these circumstances, as
it could lead to some frustration to both the asker and yourself, as you might have missed what the asker wanted exactly. Can you help them to prevent the closure of their question before it happens/help reopening the question with them?
All of these efforts should be scaled relatively to the potential impact of answering bad questions: as small as a mouse 🐭. Don't go on a witch hunt and don't repeatedly remind the same person about improving questions, that's demanding too much from occasional or busy contributors and possibly seen as harassment. Also, not all questions can or will be salvaged by the author, so you might want to strike only at questions where the asker's investment is clearer.
Don't remind every answerer either, we don't want a comment festival :).
Finally, don't ever order the answer's deletion or edition to "help" the asker: that's something that must come from the answerer themselves to avoid unnecessary frustration and arguments. As much as askers have the right to ask, answerers have the right to answer, both being the site's main purpose, after all. This goes along with knowing people might just not have the time right now for such work. Not having all answers on-point after the question's improvement is a sad possibility, but something no one really can do anything about, either.