The worst XY problem is knowing you want to do Y, even if its strange or whatever, asking how to do it, and people asking you "why do Y? Do X instead". Happens all the time in Stack Overflow. Just answer the fucking question, and then give the lecture on why you think it should be done that way, or why it shouldn't be done at all...
There are a few people who frequently have this complaint, but I don't think it's a real problem. If you actually need to do Y in a situation where most people who think they need to do Y are wrong, it's not everyone else's responsibility to divine that you are the magical case. It's your responsibility to demonstrate that you actually do know what you're doing. This isn't something you do by discussing how unfair ot…
I've never asked a question on Stack Overflow, but many, many times I have entered a question into a search engine, received a Stack Overflow link with my question at the top, and been greeted with several screens full of text none of which is an attempt to answer the question.
In other contexts Stack Overflow's conventions are set up on the understanding that they're trying to produce a curated database of questions with their answers, rather than acting as a technical support forum for individuals. It's a real shame that culture doesn't extend to dealing with this case properly.
(The most common case is where the question is something like "does A provide a function for doing B?" and the correct answer is simply "No".)