In fairness to the OP, the "red" is the tank, the "yellow" is the archer, and as I see it, the tank started off with "you aren't too bright, are you?"

Hostility works both ways. You can't ask for a non-toxic community from the "elitists" and then when someone gives you logical advice (read: when your healer is telling you as the tank not to do something, and is backed up by someone who main tanks events) tell them they're stupid and ignore the advice. If I was the tank and my healer gave me that advice, my first thought would be "I must be making it harder on the healer. Let me not do that." not "dude I know what I'm doing, you're stupid. Let's get into a pissing contest over DPS!"