I think it's far from self-evident. Dantonio was an assistant at MSU under Saban for six seasons, and prior to that was a GA at OSU under Earle Bruce and an assistant at Youngstown State with Tressel, and later DC at OSU under Tressel. Dantonio has spent a huge portion of his coaching life at institutions that are rabidly anti-Michigan, and on top of that he's a close personal friend of Tressel's and admires him greatly:
There is no evidence anywhere that indicates Mark Dantonio has any respect or regard for the University of Michigan, which is in direct contrast to Bo, who openly admitted that when he was young he admired Michigan, even though he'd grown up in Buckeye country.
Does this mean that Dantonio would have turned down the UM job if it had been offered to him? No, but that doesn't mean Dantonio was coveting the UM job and is bitter about not being considered. That's a huge leap on your part with no basis of support anywhere in Dantonio's record or statements that I can find. I have no doubt that he hates Michigan, but there is no evidence that that is a product of anything other than his coaching experience and his personality.