He certainly does not have a great range as an actor, but then again, neither does Keanu Reeves, and we know by now that, so long as Keanu is put in a role that suits him, he can be just about the best at what he does.
Are Butler's problems just a product of repeated miscasting (I mean he clearly cannot do any accent other than Scottish, so people should just stop trying to make him)? I dunno yet, but he's been miscast A LOT.
Despite all of the above though, there is something strangely likeable about him, even if I can't quite put my finger on it. Maybe it's that, while he's undeniably handsome, there's always something a little bit grubby about him, as opposed to so many Hollywood stars that either come across as too clean and preening, or more of the 'body-builder attempting to act' of the 80's model. As an action star, he comes across as more relatable than many, kind of like a back in his prime Bruce Willis, except Bruce Willis got to be in far more good movies.