This is patently false. Almost all pugs can do this with 3 healers and the fight is incredibly easy. Join a vent, spread out, and listen to the leader when he calls out when someone has a kobold and you will clear phase 1 easily. In phase 2, put all your dps on acidmaw and if you get poisoned (as shown by turning completely green) run to the fire tank. As for the last boss he is super easy and all you have to do is run out of the way when you have a 100%+ speed boost for his random charges.

The only way you won't be able to clear the timer with 3 healers is if your dumbass dps each does 1000 to 1500 dps. In that case they should either go learn how to play or do some damn heroics or nax10 first (content which they have probably not done anyways).

You only need 2000+ dps going with 3 healers. If you spend any time reading on your class at all you can do this in blues. If you get nax 10/25 gear you can easily do 4k+ for most dps classes.

If you group with bad people and are unable to recognize it you are probably a bad player yourself.