Ditto. I have a few friends that are disabled and if not for trikes they wouldn't be able to ride. Doesn't really matter what you think if the law says different.
Texas:
"Motorcycle" means a motor vehicle, other than a tractor, that is equipped with a rider's saddle and designed to have when propelled not more than three wheels on the ground.
Arizona:
"Motorcycle" means a motor vehicle that has a seat or saddle for the use of the rider and that is designed to travel on not more than three wheels in contact with the ground but excluding a tractor and a moped.
Queensland:
If a tricycle complies with the Australian Design Rules, it can be registered in the same way as a motorcycle. It can also be ridden wherever motorcycles are allowed to be ridden. A motorcycle licence is required to ride a compliant tricycle on the road network.