UFC fighters dedicate more than half of their lives and only a small portion of them ever get main card status, while CM Punk comes in with no fighting experience and get handed a silver spoon. Can't blame them for feeling that Punk's UFC spotlight was unearned. It's just like pro wrestling, when Batista first came in and got massive push, a lot of the guys in the locker room weren't too happy about that.
After a performance like this and you still get main card status? Yeah, not a lot of guys are gonna be happy about that