The point is that SO is actually less about the person asking a question. That is only one person.
But people look for already asked questions by searching for them. And I don't think that there are many things that are more frustrating, then finding a questions that describes your problem X perfectly and it has only answers to Y.
Since SO exists for the readers and not just the asker, I think that makes it even more important to highlight all the reasons not to do X if it really is unlikely to be the best solution.
Maybe the asker really would be best suited with X due to some contrived circumstance, but is that true of everyone else who finds the thread too? Probably not.
But people look for already asked questions by searching for them. And I don't think that there are many things that are more frustrating, then finding a questions that describes your problem X perfectly and it has only answers to Y.