I don't think anybody is threatened by it. But I highly doubt that pro-hockey players are playing NHL09 (or insert your sports game here).
My problem with guitar hero is:
That it seems to make some people think:
A) Playing guitar is easy to do
B) That simply because they've played the game they actually can play guitar really well.
However, I've made bunches of money off of students who decided to learn to play guitar for real because of the game so whatever. Although I do believe it stunts musical growth. If I have another student ask to learn songs and hand me what appears to be a tracklist from guitar hero I might injure something.
Actually I know for a fact that a lot of footballers (soccer players) play Pro Evolution Soccer all the time. I know a lot of NFL players play Madden. Not so up on hockey or baseball, but yeah I don' t think that's a particularly good argument.
Look, it's just a game. I'm not saying everyone feels threatened by it, but you know there are one too many guitarists out there that have a hatred for the series that is over the top an unjustified.
I don't think the game desingers tried to make guitar look easy. Nor did they try to make it appear as if you could actually learn guitar from playing the game. That's all stupid kids. And they'll find out quick enough that it doesn't work like that.
I think the problem comes for most guitarists, as it does for me, in the fact that we actually spend a lot of time learning a certain piece of music and then once we've mastered it we're really proud. Then, if we try to do it on Gutiar Hero we can't play the same thing at all. Not only that, but it doesn't even come close to resembling playing it for real. And then a 10 year does it on GH. We shouldn't care but the part of us deep inside that always has to be right, we all have it, thinks, "I can really play that song, this game isn't anything like it, I swear!" And we proceed to argue with a 10 year old about how it's not like playing guitar for real etc.
Pilots don't get annoyed with game flight simulators, athletes don't hate video games about their sports, why should we? They'd laugh if someone was foolish enough to assume that because they mastered the flight smulation game they think they could fly an F-15. Of course that's impossible. It's the same with Guitar Hero. And aside from a few 7-12 year olds that need to get some more sunshine, everyone knows that. So don't argue with little kids let them believe what they want, the majority of fully functional brains out there know this, in no way means you can actually play guitar.