I try to give supportive comments when I can. If I feel I have advice or a suggestion to offer, I do so politely. My personal rule is that unless I know I can do much better, I have no right to complain about anything.
This poll really sucks! Just kidding! I notice people getting really upset by thoughtless comments every once in a while. I think it's a mistake to take many of these comments seriously simply because so many people on this planet are clueless wonders. Some people get 99% positive feedback but pay more attention to the one guy who's clearly got a stick up his ass. It's important to be realistic and be able to take criticism from jerks and experts, alike. Mostly, though, people are extremely supportive on Deviantart. Thanks everybody! This site STILL ROCKS!