Often, I face myself asking a tricky question where someone interested in giving me a constructive answer would have to sit down and think. They would also need to care about my question and my problem and be open-minded. Instead, they often end up just trying to make a point - the point they've had all their lives and they won't reconsider - or make me bad or show off their (sometimes questionable) knowledge. In short: useless and not constructive.
Usually, this doesn't happen when the question itself is technical and can be answered very objectively. But as soon as I'd like a subjective, critical but constructive answer, I get a bashing. And even more so, the bashers get votes by other bashers such that the really constructive, interesting answers will move down in ranking among all the answers.
Is there a way to circumvent that? E.g. in phrasing my question very carefully (how?) Any ideas welcome.
NOTE: Downvoting or flagging them is maybe not the best option, because they may still have a valid point, but they did not answer constructively.