He made it pretty clear in one of his promos where he was asked the question of whether or not he had one more title run in him. One more title run was his goal. I don't feel there was ever any misleading that he was looking for more than that. Is that to say he won't ever come back? Nah, but I don't think it leaves any type of hole in the storyline.
If he had went for his rematch this place would be up in arms crying like hell reminding everyone that he said said he only wanted one title run and calling him a liar.
It's because wrestling is FUCKING FAKE. You can make rules and stick to them when it suits you. He wasn't booked to have a rematch because he's a selfish bitch who wanted to come in, work 7 minutes and leave.