So many of these guys give us rational and legitimate reasons to dislike them it's tough to find irrational ones. I agree with Disturbed that Ethan Hawke is pretty greasy, though. AG in NC
johnson8861,
The OPs original question specified irrational and unreasonable. The first two on the list (never seen the kid in anything) have more than a few pretty damned good reasons to hate, despise and loathe them. I'd say that's just good common sense. And yeah, screw 'em.
So the OP's question is/was actors you hate...
drew Barrymore. hate her pouty/whiney roles.
Marky Mark, single handedly destroyed more films than humanly possible. However, I just can't stomach him for more than that yet think his brother is a decent actor.
Anna G, whatever, Skyler White on Breaking Bad. I'll never forget WW saying, "will you get out of my ass?"