I think you are absolutely right - tradition, facilities, fan support, etc - all of these things contribute, as you say, to the disparity that has forever marked college football.
I do believe, however, that proximity to talent is, far and away, the single GREATEST and LARGEST disparity that exists in the game and Nebraska is the only blue blood program lacking this natural resource!
That Tom Osborne managed, nonetheless, not only to win but to win with a consistency unmatched in the annals of college football is why I feel certain that he is deserving of the title of modern day GOAT.