Let the kiters have fun :)
I mostly agree with the OP, except for those obvious exceptions like bosses.
If a player aggro mob(s) and kites them away from the party, I'll assume that he can either handle it, or will bring the mobs back to the party. If not, he'll (hopefully) learn to. You'll never see me chasing after mobs chasing kiters.
If a kiter want to play with a few mobs on his own, I'll let him. Some players might kill them as fast or faster than any melee, while others might use a minute or more per mob. As long as they don't hinder the rest of the party I really don't mind either way.
Oh, and if I'm on a ranged character, go for those enemies ahead of us, and stop chasing the ones i'm having full control on. They're probably dead before you get to them anyway.