I do think Avril is cool because she doesn't take her clothes off, but I do have to say that this last album of hers was really bad compared to the other ones. She sounds very immature and whiny, instead of more mature (since she is indeed older than she was when she made her previous albums).
Also, I have to say that there are certainly other artists that don't strip down to the core in order to get popular, just look at Kelly Clarkson or Alicia Keys. I think many artists aren't viewed as sex symbols.