Guitar Hero is just another video game. The people who get REALLY good play because they like the video game, NOT because they want to play guitar. If they wanted to play guitar, you bet your bottom they'd go buy one. The only difference between GH and any other video game is the shape of the controller. Otherwise, in both cases, you're carrying out the intended task in order to score the highest, beat the game, etc.
I don't think I've ever seen this before. People have gotten after the gaming community for spending too much time playing video games instead of doing something more productive, but fellow gamers? Who cares how much time/money people are investing in Guitar Hero? They're just playing another video game! Just because the controller is shaped like a guitar, people feel like they need to bash the whole idea, Why-don't-you-go-play-a-REAL-instrument style. Oh yeah? Why don't you go stomp on a REAL goomba? That's what I thought.
I am a musician as well. I have been playing trumpet for over 5 years. I love it to death. I also love Guitar Hero. Why does there have to be a border? I'm appalled to see such ridicule coming from fellow musicians/gamers.