Well, if I go to a Christian forum to say God doesn't exist, people would probably label me that because it is obvious I am on purpose looking for a reaction, that said it is true that people tend to get out hand labelling people as troublemakers simply because they express something different.
That said I believe the way we express ourselves can also contribute to have an hostile answer back or that we're there just to cause trouble when what we really want to do is to get our point across. I could say more but I already stood my ground in the other forum.
It is actually quite funny once you find how easy some people get offended for what you'd think are silly things.