Tank entitlement vs group entitlement

[Tlachtga]

Also, its not always not knowing your class, its sometimes the comfort of how you want to play. Some people prefer a relaxed pace, and some prefer a fast pace.

These are not mutually exclusive.

I think its unfair to expect high synergy at the most casual of group content (duty finder dungeons)

It's not "high synergy", it's basic competence.

If you're doing 70 dungeons while decently geared and you're not pulling everything, you're being lazy.