
Looking at the average age of any given person on a production team for any cartoon from the smurfs to la blue girl, I am PRETTY sure you'll find many people way over the age of 20. Who do you think writes the material for the Simpsons? A 15 year old kid? What about South Park...does this mean they are all losers for working with cartoons?
well on the other hand, I know you are talking about a hobby here and not a job. People will do just about anything to get paid

What's with the assuption all people over age 20 that haven't already gone out and sprouted themselves a family or who can find enough spare time to have hobbies that involve making anime music videos are somehow warped in your mind? Keeping the earth nicely populated and working a desk job may not exactly be the dream of everyone over the ripe age of 20, if you hadn't considered the possibility.