He can be really upset that BYU didn't hire him as the head guy, but he had interviews at several schools who also passed on him. Stanford Arizona, etc. etc.
He had a lot of interviews especially after winning at USC (as an OC) and but it didn't work out for whatever reason.
Hawaii finally gave him the head gig in a not-so-great situation and he went 10-36.
Being a head coach that wins is really, really hard so it's not the end of the world if it turns out you don't have what it takes. If the best parts of your career were being an OC and the worst parts were being a head coach, maybe it's not worth a lot of time being bitter about the people who told you "we don't think you're the guy to be head coach here."