I am betting against Guitar Hero. It is certainly not going to raise awareness of the contributions made by my heroes e.g. Jimmy Page, Hendrix, SRV, Johnny Winter etc (the list is long). Bands like Indigenous don't get any air time today because Kurt Cobain made it OK in the early 90's to suck at playing guitar—or so I maintained for many years. I graduated from high school in 1995, and that's about the time I decided that rock had been effectively killed. Several good bands peaked around that time, but how many have followed since? I have struggled to find new bands to really get into since then, and am continually disappointed by the bland mediocrity that all the alternative-esque, uninspired garbage on the radio seems to be these days. The truth of the matter is that Nirvana really was an innovative band, but so many of the bands that followed them lack any innovation despite being able to learn power chords. Do we blame Nirvana, or do we blame the interest in rap and hip hop that has simply stolen the focus that worthwhile rock needs to flourish? I don't know.
I have friends that actually like Guitar Hero, but I do not know if they have any sort of musical training, interest, or talent. While I have always tried to ignore the annoying game the few times I've been exposed to it (at least it's not karaoke), to my surprise, I heard a Buckethead riff one time and asked “is that Buckethead? Bucket head is awesome.” I got a “yes, that's Buckethead” in response and no comment on his music. Honestly, I struggle to like Buckethead. Talk about raw talent in an individual who can't figure out what his thing is, and who apparently can't figure out or desperately wants to avoid appealing to anything remotely mainstream. Maybe he thinks if he sold out he would become Joe Satriani 2.0. He could do worse.
This game is probably not creating a musical interest in 30 year olds, and I would imagine that the teenagers who are really into it are the ones that “just kinda like all music” and don't put any thought into much of anything. Game over.