IMHO, a couple of things come into play here:
*It's Alabama. Long runs of success will always bring out haters because they want to be us-though they won't admit it.
*Everybody hates a winner that basically points out that the reason they aren't winners is because they aren't willing to work hard enough. CNS isn't really considered a "guru"--at least not on the level that Bill Walsh, LaVelle Edwards, Monte Kiffin and others who revolutionized some aspect of the game are.
*Media-They need to sell a story and CNS is an easy target. Bama fans will basically give you all the free pub you need by arguing the point and posting the article link everywhere and flooding message boards which just sets everybody else off. Fish in a barrel.
*He doesn't have a contemporary. Miles could be he's so aloof that no real CNS-CLM rivalry story really works. No other program has been anywhere as consistent so CNS stands atop the mountain and we all knkow the game "King of the Hill" goes.
*He's preachy. He doesn't duck or shirk responsibility or criticism. No one claims we're FSU or AU (except maybe FSU&AU). He seems to hold the moral high ground despite the Satan references.
*He doesn't pay you any attention. For the most part, minus the 2012 aTm game film, you don't get to be on his mind any longer than the 1 week of your game with Alabama. he doesn't pay you any attention before that and he forgets you by late Saturday night. CNS/Alabama stays on the collective minds of CFB but you mean nothing to him. Ticks people off.