I have to agree 110% with Casey. She hit it on the head!
I think the problem is you are comparing ball pythons to all of the other animals in the pet trade. Can you honestly think of any other snake or reptile that is easier to manage, incredibly hardy, very unlikely to strike and comes with a low price tag?
Everything about ball pythons is easy compared to other snakes. Corns are flighty and often poop on their handlers, milks and kings musk and pee, that is a big turn off for people. They may have different requirements that are easier to meet (as in, a heat lamp is sufficient), but by far I would rather handle a ball ANY day over a corn snake!