Boise also had Dirk Koitter (spelling is way off on that) before Hawkins...Franchione started the building process at TCU.
Most programs don't keep the guy that starts the building process. It is up to the guys who come after to keep the process moving forward.
And for your comment about "the grass isn't always greener, only the paycheck". TCU is one of the most funded football programs in the FBS so it is not like he is at a school that is struggling to make ends meet.