Have you noticed that there are some hobbies that are not okay to spend too much time on? I have known a few golf fanatics in my time -- I even caddied for them! -- who spend literally every daylight hour of every weekend at the golf course, and even some afternoons during the week. I've known a few car fanatics who spend all weekend working on cars, motorcycles, or other vehicles, sometimes spending large amounts of money on trivial cosmetic restoration tasks. Every fall in the northeast US, who doesn't know some hunting fanatics who are out before dawn, in the cold, waiting around to shoot, clean, and eat an animal of some kind? Then there are the sports fans... I mean the really hardcore ones who follow every member of a team, have the fancy cable or satellite package that lets them see every game, and scream at the TV whenever a game is on. Ever met a railfan? I say no more!
These things, and other traditional hobbies and free-time obsessions, seem to be an accepted part of the culture. But get into World of Warcraft or some other time-consuming computer or video game, and the rules change. It's okay if you waste your time and money on certain things in the name of having fun in your spare time, but WoW has this stigma attached to it. I guess maybe because it's a game, and games are associated with children, not adults, so to some people Warcraft is a childish pasttime. But so is getting worked up over football games, and playing with cars, and making model trains.
I don't see these things as childish at all. We tend to associate play with childhood, though, and so it seems childish to have a sense of play as an adult. If you wonder, explore, and imagine, and find some creative way to channel those internal energies into a physical outlets, then you are in some way playing. It doesn't really matter how you play, as long as it's not self-destructive or harmful to others. It's a shame that some people can't accept that.