It actually seems the other way around to me. Many of the Federer fans on this board seem to be teenagers or in college. Probably the appeal is based more on character traits and the things we admire about people, moreso than on groundstrokes.
No, Nadal fans are younger kids who see Nadal as some kind of a superhero (they will see the truth about the cheater when they grow up). Tennis fans, the ones who actually play the sport, usually cheer for Federer.