You can edit your first post to include the extra material and delete he 2nd for a cleaner look if you like.

I think the answer may be that a lot of players come from a single player gaming universe, and so they are not really expecting, or wanting unsolicited opinions, especially annoyed and judgmental ones, demanding that they step up their DPS, and if not, calling them a 'bad' or simply crap at their job. So, when they are playing, and doing adequate DPS in non-end game they feel there is nothing wrong, mobs are dying, so everything is fine. Then they get into a group for end-game/raiding and suddenly other DPS are doing twice their DPS and demanding to know why they are not keeping up. It's a rude awakening for some.