Guitar Hero fans usually hate the Rock Band guitar controller and vice versa. Instructables has a pretty good how-to that can solve the problem for Guitar Hero fans at the cost of a Rock Band controller. It's a way to mash up an old PS2 Guitar Hero controller with the Rock Band Fender guitar and make a perfect hybrid with raised keys a clicky strum. You could just use an Xbox 360 Guitar Hero controller for Rock Band if you're on an Xbox 360, but where's the fun in that? [Instructables]
I don't understand this game either but I wont hate and to each their own.
I play guitar and tried to play GH but was ultimately frustrated because I actually know how most the songs on there are really played. I kept trying to hit the actual frets instead of the buttons, as you can guess I suck pretty badly at these games.