The game should at least have a personal parser. It is really hard for a new dps to know whether they're making any actual progress or compare their performance to the others. Doing the mechanics well=/=playing your class well.

It's funny to what extends SE goes to protect the pride of some dps. If a healer messes up, people die. If a tank messes up, people die. If a dps is being a wet noodle, they somehow have the idea that no one should be able to tell them something is off... although you can already tell underperforming to an extent via the enmity bar. It's a touchy subject; even if you're friendly and nice, even if you tell it only to the person themselves, some people will get really mental about someone commenting about their dps. But why pick up a dps class if you don't want to dps?

I have never ever seen anyone kick people out for lack of dps.If anything, people have asked whether they pull their rotations right.