I think one thing you will notice about America is that there is this general undercurrent of fear concerning dangerous things (motorcycles, guns, propping plywood against cinder blocks and jumping your bicycle off it, etc.). It's not everybody, but this culture of fear has been growing and growing over the past few decades and a lot of the tools that I was taught to use growing up are now considered too dangerous for people to use and need to be controlled by the government. In this same vein, a lot of people don't view motorcycles as an enjoyable way to get around and maybe save a buck on gas, but view them more like one would poisonous snakes or DDT - something to be avoided because "they might kill you". In my opinion, there are plenty of things out there that might kill you, but one can generally acquire the skills necessary to use these things effectively whether they be a motorcycle, baseball bat, claw hammer, or a firearm. I think this is one of the chief reasons you don't see more American motorcyclists, but I may be wrong.