Why did he never really become an a-list star?

I wonder why Dafoe's never really become a major star in Hollywood. Sure he's still a relatively successful actor but early in his career he had the makings of being a major star. He had critically acclaimed roles in big Hollywood films like Mississippi Burning and Platoon but eventually he's become something of a B-list star. Was it because he wasn't the typically good looking leading man or was it a conscious decision on his part that he chose projects that weren't necessarily going to appeal to a mainstream audience? Perfect case in point being The Last Temptation of Christ which considering it's controversial nature might have career suicide. It's not necessarily a bad thing, I'm just curious as to why he never did.