For some reason every "expert" who has a chance to comment on this has only been looking at one side of a complicated story. Its true that if Keller had stayed at ASU he probably would be starting next week. What no one seems to remember is that he was named the starter and had it taken away. With the way Koetter put all his credibility on the line in changing his mind, its understandable that Keller felt he wouldn't really get a fair shot at ASU both because Carpenter must be a decent qb and also because Koetter would feel the need to stick to his guns this time.
On top of that, Keller's getting 2 years to learn the WCO from a former NFL head coach and will inherit a very talented and experienced offense to run next year. It blows my mind that everyone's willing to talk about spoiled athletes who take their ball and go home, when in reality its more like he was run out of town.
I don't think there's anyone out there who wouldn't have done the same thing he did, no matter what people say. If he's really got the skills to play at the professional level, which most "experts" seem to think he has, then it would have been foolish for him to stay at ASU and ride the bench his senior year.