You also have to figure that since the stuff is so much cheaper, and the sport is more exposed over there, they have a wider variety of people who play. If you don't have a ton of space and you do have a ton of people things are more likely to go the way of paintball (run and gun).
Here you have to be a bit crazy to spend the few grand you'll need to do it right. The people who aren't serious will go for the Canadian Tire springers or pellet guns. The ones who are serious are more likley to be into milsim.