Mario is just as recognized as Mickey Mouse by millions throughout the globe. Everybody under the age of 15 is in love with Pokemon. Nintendo has proven to have a stranglehold on the portable gaming market with its' Gameboy incarnations. All of that equals money, tons of it. Video games are NOT just for kids any more.
Adults do indeed enjoy playing video games.
It is slowly becoming a part of our cultural and social fabric. I am 24 years old and I've never known a life without video games and there are many others out there like me. Sony proved to be successful in the video game business because it specifically targeted the 18-24 year old demographic. They attacked that demographic it for its' buying power and it worked. They went ahead and secured a good piece of the gaming market with the release of adult oriented games.