The problem is obsession not the game or activity.
Right on. And on the other end of the spectrum there are parents who get so over-involved in their kids' lives that their kids start playing WoW to try and get away from it. It would seem that some people have a greater propensity for addiction to certain things, but for now I'm still thinking obsessive behavior is still the culprit.
No one gets sick on Wednesdays.