I've seen dismissive posts like the LOL post from many different sources. I don't like any such post, but that one's no worse than many others (apart from its lack of specificity, which is not unique to that post either--it didn't tell me exactly Coach was disagreeing with).
I'm all for increasing civility on the board, but it would have to be across the board. Calling a post idiotic or telling someone to put down the crack pipe or anything along those lines is just as bad and we've certainly seen those kind of posts here many times.
Telling someone where they're wrong or why you disagree with them is one thing; demeaning them or insulting their intelligence is quite another. I'd love to see the latter end (and if I've been guilty of such posts in the past, and I probably have--shame on me, too).