Classes have hate shed abilities that make it difficult to use the threat meter in game to gauge who's performing well. If you PUG two DPS for Coil and cant clear Turn 4 are you going to just boot both PUGs? What if one of your static DPS is just having a bad night? At one point we possibly could have kicked our now static BLM when we picked her up as a PUG when it was the PUG BRD who was falling short. Sure you can look at the battle log every so often or the onscreen graphics and notice a DPS isn't using certain abilities or combos but you cant always manage that.