If I took a new job and then a year later got offered one about 2.5x as good I don't think I'd be a dbag for taking it, personally.
Seems to me that OSU didn't really treat him as well as they should have from the start and he sort of took a flyer on THEM by staggering his contract the way he did and proving he could win before getting paid real power six money.
As always, the kids who follow these coaches are the ones who actually get burned the most by all of this. But what difference does it make if he leaves those kids now or 3 years from now really? It will happen at one point or another.