Where is he under appreciated, I wonder? Here on this site? Indeed, but that is not a surprise at all, considering the community.
Otherwise, IRL? Not so much.
He is, rightfully so, considered the greatest Rock star that ever lived. His legacy surpasses the likes of Elvis, Jackson, Lennon etc..
Nearly a half decade of influence and creationism, that is unmatched, and will be so for a long time to come.