Plus, all the kids will quickly learn about something called "calluses".
"Mooommyy, I don't like this game, it hurts my fingers! I just want to push plastic buttons!"
Admittedly, I have started learning recently, and the callus thing didn't cross my mind prior to trying out a guitar for the first time, although I should have remembered that aspect:
Me: "I seem to be getting some weird vibrations."
Friend: "Your not pressing the strings properly on the neck."
Me: "Is it supposed to hurt that much?"
Friend: "You'll get used to it after a few weeks."
Me: "Oh...."
This Guitar Hero development seems pretty cool since you're learning the actual finger positions.