It is not our job to help you overcome writer's block
If you think about it, the moment you start asking for a list of ideas to overcome a problem with your story with no one of them being the best answer, your question is too story-based. This site is dedicated to creating the world of your story, not your story.
Worlds are about systems
And systems are objective and definable — because they must be reusable and operate consistently and predictably without interference from the specifics of one story. In that regard, they are exactly what you're unhappy with: universal. A world is a place where an infinite number of individual stories can take place, and so we address rules and systems. For example, how can I make natural rain on my world appear magenta? This question is about the system of the world: the environmental process of raining.
Stories are about circumstances
On the other hand, if you ask, "my mad scientist did something and now the rain falling over Megopolis is magenta, how'd he do that?" you're now asking about the circumstances of your story, not the rules or system of your world. Basically, justifying the actions of an individual character. That's not what we're about at worldbuilding (not storybuilding or characterbuilding) dot-SE.
Separating the two...
Unfortunately, a great many people are building their world at the same time they're writing their story — which makes it very difficult to separate the two perspectives. From such an author's point of view, a storybuilding question is a worldbuilding question. You, the original poster (OP) of a question, are required to know the difference between the two.
It should be noted that the question of allowing storybuilding questions has been regularly asked on this site and regularly rejected. If you think about it, the site would no longer be about worldbuilding almost overnight as the number of storybuilding or "help me overcome my writer's block" questions outnumbers worldbuilding questions 1,000:1.
Does this mean there's no place for list-of-ideas questions?
Or course there's place. While asking for an infinite list of ideas is off-topic, asking for a finite list of ideas is not. It's up to you, the OP, to narrow your question so that it can be answered in a practical way.
Can I depend on Worldbuilding.SE to apply these concepts universally
Nope. We try our best to get people to consistently follow the rules, but for a thousand reasons they don't. Generally Speaking we're pretty good at helping everyone (new users and experienced users) to follow the rules — unless the question is a really cool question that tickles the fancy, then we really suck at it. However, as painful as it is (and every one of us has suffered the "learn how to ask questions" lesson...), it is important to learn how to ask questions properly. When you do, the questions are much more valuable to everybody — including and especially the OP!
Here's the important part...
The fundamental problem is that worldbuilding.SE is NOT an OP's all-volunteer personal reserach team. That's a really harsh way of saying it, but when all you want is for us to come up with a (fundamentally infinite) list of ideas from which you can casually select a convenient answer, that's what you've turned us into. One of the fundamental attributes of Stack Exchange (and this is their site, not ours) is that questions and answers must serve everyone. Not just the OP. In other words, as you ask questions that are more and more "just what I need" you come closer to violating one of SE's basic tenets — helping everyone.
Therefore, yes, the ideal Stack Exchange (you'll notice I did not say "worldbuilding") question is objective, narrowly scoped, and leads to a single best answer (aka, a "single true answer"). We respect the fact that Worldbuilding is a creative and imaginative process and some lattitude must be allowed — but only so much. The more effort an OP puts into asking a question that meets both SE's and Worldbuilding's standards, the more likely the question will be well accepted and remain open.