Okay, fine. I'll actually bother to give a serious response to something on this cesspit of a forum for once.
DPS are typically left alone because a large majority of players aren't observant enough to notice a DPS being lazy/doing dumb things... which is a shame, because that means they get away with it and continue to drag groups down. Seriously, don't join content through the duty finder if you're just going to be lazy and/or you've never even bothered to read your jobs skill descriptions. I mean, really now? Really?
Healers are typically not bothered unless the party wipes because as long as they aren't dying, most players don't care what the healer is doing. And no, I'm not saying healers don't get blamed for things they weren't the cause of, so don't even start.
Tanks are by far the most likely to get yelled at, regardless of what skill level they are playing at. Because hey, guess what? Tanks are obvious. Tanks control the general flow of a dungeon, it's their job. Everyone can see what the tank is doing, it's the most visible role in the game in terms of the impact it has on a fight.
You could be the best tank in the game and it wouldn't matter, because as soon as you did something using a method that someone else in the party doesn't know, they might get annoyed and start yelling at you. Even if what you did was a smarter thing to do than what they were expecting.
Oh, and by the way, I've tried giving nicely worded/presented constructive advice to players of all roles, and you know what I usually got?
Silence.
"Shut up."
"fk u i play how i want"
Vote kicked.
You want to know what the real problem is? It isn't a specific role. It isn't a specific job. It's just a portion of the general playerbase being jerks. A lot of them are just jerks by default. Maybe some others get a kick out of trolling people. Some of them were simply just having a bad day, I'll fully admit I've been guilty of that.
Tanks are typically the most visible role in the game, and therefore the most likely to be yelled at about something... anything. So go ahead, keep claiming tanks that have gotten tired of being yelled at are the problem, it won't change the fact that the real problem isn't tied to a specific role, or job.
PS - I main dark knight, and I don't avoid going into DF solo. Not everyone in there is nasty, and I've met a lot of cool/amusing people doing so.