Fedor is good enough to fight in the UFC still, however his name is so big that the UFC doesn't think it's worth it for them to pay the big bucks for a fighter who, judging by his losses, is probably not a top 10 heavyweight. The UFC probably doesn't want to mess around with the controversy of having someone get paid so much for their name. It wouldn't look good if Fedor lost, and they probably wouldn't really want Fedor to win either, because then the hype machine might get going again.

Of course, if Fedor wanted to fight at light heavyweight, or middleweight, which should be theoretically possible, and suddenly he has a six pack and does tons of cardio... then I think he could get a UFC contract, but somehow I think that will never happen.