This is also my definition of troll, and has absolutely nothing to do with disagreeing with one another.
To expound... I don't think anyone needs to earn their right to be here, or even contribute in any way. I lurked here for a year without even making an account, and I bet there are plenty who still do the same. That said, if one's sole purpose for participating is to disrupt the thread for their own enjoyment, then they're trolling. If you don't like the thread, and can't participate without being a pompous prick, don't participate. If you can only respectfully and productively participate in threads you find interesting or agree with, but none of those threads happen to be gun related, then you're probably on the wrong forum board.
I typed out considerably more, but I'll save it for PFestivus.