If you can find me an episode of that show, that has not been taken down from youtube, I'll take a look.
Heard that episode was quite good.
I say let the people who play GH have their fun, some people I know are pretty good and established guitar players and they enjoy playing a round of GH, even though its hard for them to play at first. :P But least it does one thing, and that is bring notice back to the guitar and maybe encourage some people after playing GH, to learn to play a guitar. Not everyone will do so, but heck least they can pretend to rock out, rather than spend a fair amount of money to buy one and then giving up later on, because it was too hard.