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, either 🦋.
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 out.
Setting the premises on
It's simple to understand, but it's harder to feel it, so let's get back to basics! From the help center, 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 recall people to not answer badly written questions. Or should we?
Epic battle of viewpoints!
A point that seems to stand amongst people that would disagree with the previous sentence is that answerers takes some of their free time to help others, so telling them to not answer will be badly received, in all due cause. It's about the same thing as you don't yell out loud at the man who brought you the wrong item from a shelf you couldn't reach.
But most importantly, the issue is that one would think a question should be closed, and the answerer did not in all honesty! It usually happens when a question is in the quality's grey area. This makes it really hard to say to them 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 it has to be taken into consideration to avoid being inconsiderate to 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
First and really important because it's needed for the other points, people are not forced to answer right now.
If there's a debate on-going on a question you wish to answer, you can just wait a little 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 people telling the reasons they're closing a question. But interestingly, I see many 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 want as few closed questions as possible, it's not on the closing's side to give counter-arguments to their closure reasons. At most, they can give directions to improve. Defending the question is more like the task of 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 edition of the question when it gets closed. Question whose purpose 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 an harder time improving them, and that can get discouraged much more easily.
Therefore remember to whom the added weight belongs to 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 defines how answering bad questions runs the risk to be felt as :
Save yourself some frustration...
As the answerer, save yourself the frustration of getting your work invalidated or be a weight 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, very lengthy processes that could 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, 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're not one). 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 too much what 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 with the assumptions I made with your world in my answer? Can I add them to your question?).
It's all in the mindset that questions and answers are intertwined : You can't really answer correctly bad questions. That's the key point of good answers, you need to have a clear, well-defined target to aim it. Otherwise you're most likely to miss what the asker wants or clumsily answering that you don't know where the target is! 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. Frustation 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 ways and reasons an answerer have in order to help improving the question. And, if the 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 but others! And this flip 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 spot to give an 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 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 is having a debate about closure? By debate, I mean at least a comment + close vote (if you can see it), comment + negative vote or several comments (counting comment upvotes). All of these should not be yours.
- If there's a debate on-going, 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 are?
If you're the only one to think the question's not good enough to be answered, or in overall it's not that obvious 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's should be
closed or not, can you explain why do 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... uh... risking. 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 detail or focus :
The question's currently undergoing a closure debate and it seems to lean towards a closure at the time I write. It is
generally not advised to answer a question in 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 this effort 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 harassing. 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 ask 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. They have the right to answer and it's the site's main purpose, after all.