I'm all for allowing it. Do you want to censor everyone to the point that you don't know who's an ass and who isn't? That's what corporate America is like, your worst enemy has nothing bad to say about you. I'd like to get out of that during my time off, and let people present themselves for who they are and not what someone else forces them to be.
Had he been so censored that all he said was "I strongly disagree that cave training is as important as portrayed." or "I wish the visibility requirements weren't quite as high, and I believe that because people dive in the river with minimal incidents fairly often" I would have a different perception of this poster.