His leaving for Colorado I understand. He was very enamored of being in demand (also understandable, but he did come just short of having an 800 number).
Rick Taylor is part of the equation, of that there can be no doubt.
But the bottom line is, Barnett was interested in "better" jobs. That he saw Colorado as one is, again, quite understandable. But even had that job never come open, he had some bags packed for a while.
I think his definition of what a "better" job is has evolved, as it would for any intelligent and reflective person.