Why? Because the world isn't a college campus. Because your "hobby" or "sport" isn't actually either of those things, as it requires less talent or skill than riding a bike. Even worse, because some of you actually call yourselves skateboarders, and you're anything but. You stand on a piece of plywood and try not to get hit by cars or pedestrians. And yes, being a pedestrian requires more skill and talent than longboarding.