I hate to be pedantic, but once again, people are missing the point of the Question.
It's not if you like someone's music or not, or if you can't understand why other people do like it.
The Question asks who is overrated - so regardless of commercial success, does the artist or band deserve the high regard in which they hare held, or not.
Which brings me neatly to my next most-overated artist - Morrissey.