While that is true, motorcycles are cheaper than cars, but you don't see the majority of people riding motorcycles. Protection from the elements and the ability to carry more cargo is the reason why most people drive cars as opposed to riding bicycles or motorcycles.
Motorcycles are more hassle than both bikes and cars (licensing, attire, helmets) and a WAAAAAAAY more dangerous (about 40 times as likely to die per mile was the figure in the California Motorcycle Safety Course, if memory serves). They're also a pretty big expense since for most people they won't replace a car, and you still need to insure/maintain a motorcycle.
I'm very pro-motorcycle but bicycles have a much lower barrier to entry.
I'll grant you that a car is more convenient for carrying cargo. But with a bike trailer, a bicycle can pretty easily handle most people's cargo requirements—anything from groceries to large appliances like refrigerators. Check out some of these bicycle trailer plans: https://bikecart.pedalpeople.coop
The cargo argument comes up all the time. No, you don't need to buy a truck for the trip to a hardware store. I know some people do, but they often visit the hardware store every day, the majority of people don't. Yet everyone drives a truck up in Montana, I mean so do I, but it was $800 and I can maintain it myself since I bike primarily.
