Exactly! Although, I think unique abilities/rare abilities like death grip are okay, in that without unique stuff we end up in a homogenisation situation where no classes bring anything cool over other classes, and I know people don't want that.
But there should be more of a trade off when it comes to unique utility, especially among tanks and healers because you only get one of them in the group. One tank shouldn't be the go-to for every dungeon, either because they bring 50% more DPS than other tanks or because they blow the others out of the water on utility/control.
DPS it's less of a big deal because there's room to fit 1 utility guy and 1 high DPS guy in your set of 3... although I do think MAJOR abilities like mass grip and shroud should get a similar system for 5-mans as CRs or Bloodlust got... some kind of global group cooldown so there's no incentive to stack multiple classes for it. Not sure how people would feel about that.