-Attempt to second guess your use case for you. Are you sure you really want to do X? Don't you want to do Y instead? (No thanks, I really must do X and can't do Y because I have Z, A, B and C constraints.)
-Claim your use case is wrong, should not exist, or at the very least is exceedingly niche, and they couldn't possibly imagine why someone would have your use case
-Claim your use case is literally impossible to fulfill with the constraints you've given. While this may well be the case it is a way stronger claim than most people realize.
-If someone does provide an answer to your use case, will scramble to insist that this solution is clumsy and shouldn't have be written in the first place because it could give people wrong ideas.
-Insist you didn't do the research and if you did you'd find the solution is Y. (Yes I did, and it really isn't Y because my problem is X, thank you very much.)
-In the worst case, wrongly mark your question as a duplicate of Y
The strength of SO is that it is purely a question and answer website: I give question, you give answer. Forums always sucked because the question askers were often new and inexperienced and formulated questions the wrong way, and the entrenched users were patronizing and insisted a certain way of solving questions be used or say useless stuff like "I don't owe any of my time to you" (yeah well why are you bothering writing this post in the first place then?). With SO's system of questions, answers and comments, everything is clear or clarified, all the chitchat is dispensed with and no room is given to subjective stuff like 'is your question correct?' Because no matter how good of a hacker you are, your knowledge can't possibly cover 100% of all computer programmers' use cases.
I'm not pessimistic as other people as to the future of SO and I still think it is and will be an invaluable resource in the following years but if trends of the YX problem go for the worse it could mean a return to the forums that sucked.