Importantly, I have changed my opinions on certain aspects of technology or politics based on rational civilized discourse that happens here. Disagreement is actually an active and important part of such discussions.
It has become impossible to talk about anything slightly controversial that detractors don't even try since they'll just get downvoted and flagged into oblivion.
[1] Subjective justifications cannot teach anyone anything, as people can't know what exactly is the problem, only that they have to shut up, because moderator doesn't like what they are discussing.