Holmes set a time limit and obviously didn't get to where he wanted in that time (if he made it he wouldn't of came back). He gave it a crack but didn't make it. I don't blame him coming back (at least he tried) when there's 1-1.2m a year waiting for him.
If he set himself a time limit as short as 12mths to learn the game to such a level to make a 53man roster, he was never really serious about it.
If he's coming back because he's worried about one years wages, he was never really serious about it.
If he comes out and says he was advised by x, y & z they he just isn't good enough to make an NFL roster, and that he'd never be more than a practice squader, I guess I could understand it. Although, you'd hope he'd have enough mettle to stick it out at least another 12months and try to prove them wrong.
Meh, its his life, I'm sure he'll live how he sees fit.