In Tiger's case, his dad has been his coach since birth. For Tiger, having a coach is natural. Bubba's dad couldn't break 100. Born with incredible natural ability, Bubba just dug it out of the dirt on his own, and that's what comes natural to him I guess. He made it all the way to the highest levels of the game doing it, so why change?
Mike said it best once when he said, "if I taught Bubba, I'd just show him swings of himself when he was playing well and show him the differences between that and when he was playing bad." I think that's all you'd need to do with Bubba.
Sure, you wouldn't use Bubba as a model, but you wouldn't really use anyone out there as a model for the perfect golf swing. Each great player is a prime example of a handful of universal pieces in the swing. In Bubba's case, straightening the back leg to turn your hips comes to mind as the most obvious move he makes to show a student that it's okay to make this move. He has steep shoulders, lag, a flat left wrist, a steady head, an absolutely incredible jumping move, secondary axis tilt, a steep backswing, a shallow downswing, and he tosses the flying wedge away amazingly well post impact.
Just off the top of my head, those are things you could use as examples to teach someone else when comparing swing videos.
My biggest fear for Bubba is one day he just goes down a bad path and can't fix himself anymore. It remains to be seen if that will ever happen though.