[quote name='evanft']Well, if you look at the guitar tracks for most of the songs, they won't challenge anyone who's decent at Guitar Hero, so after the first few days, everyone will pick up the drums.[/QUOTE]
I think there are still a lot of people who will appreciate the easier guitar. I'm decent at GH (beat the first 2 on expert...working on GH3), but to be honest I have more fun playing songs that are easy enough to be able to play and not have to focus so much on hitting a billion notes at a time (GH3, I'm looking at you) . I think it lets you get more of a feeling that you're playing the song and not just banging on buttons.
Plus if you are really good at guitar and you're playing in a band, you can really help out the score because multipliers are multiplicative...i.e. if the guitar player has a 4x, the drummer a 2x and the singer a 3x, the total multiplier for everyone's notes at that point is 24x.