As for the game Guitar Hero, I suspect it's just another way of sticking the kid in front of a tube so that parents can get on with what they want/have to do. It's all right, but only for a while.
In a nation where the Center for Disease Control says that 25% of the older girls have a sexually-transmittted disease and one baby out of 50 is abused or neglected, I believe that parents need to spend more 'quality time' with their children. A lot more.
And if Mooh, who actually is a guitar teacher, says it doesn't help guitar players, then I believe we should value his opinion.