Well its not the healthiest of habbits compared to hobbies like sports but neither is watching TV; so really its far better than watching TV. Its bascially like reading an interactive book, people say reading books is very healthy and good for you. I say it depends on the book! Just like it depends on the game =] Either way at least your brains working unlike TV where nothing is working. I guess older people just don't see it as healthy because it involves a TV? Not all "older" people think its bad though.
I love this sketch: