Wow that puts a new slant on things, never would of thought of that.
My boy has done Karate, Kick Boxing and now Judo at the ripe old age of nine. He likes Judo the best as the others just seemed like a whole heap of move and various exercise, with Judo it was straight into fighting and this pleased him a lot.
I can see your point about the above but I'd rather not think about it like that, it's the paying bit that makes it a bit suspect.