Oh I dunno… maybe they haven’t spent the last six months in the beta practicing dungeon runs. Maybe this is the first or second time they have seen the instance and it’s all new to them?
Same with heals, and the derpy DPS.
Give people a break.
If you want super fast clears to gear, go get your guild group and run them. You can all leave after the second boss and reset the instance. You can run whatever instance you want in what ever order you want. You can skip packs or not, while you perfect your gogogogo Mythic++ eSports strat.
What’s not to like?