Why would it... Some actors are just **** no matter the roll/casting and a lot of them are on this list.
You're not getting it.
Thread is about being amazed at actors getting cast in the roles they get.
Actors rarely cast themselves do they? For them to even be there someone else has decided that actor is perfect and they should have the role.
Unless the actor is phoning it in and doing worse than they usually do it's the fault of whoever decided they were perfect for the role.
For example I agree Martin Freeman is super limited in his acting, besides the costume he's the same in every performance. But that's what he does. Someone else is copy pasting him into films over and over thinking he's just right and that's someone doing a bad job.