I can tell you why I am in support of captive breeding just about any animal. It keeps them from going extinct is probably the number one reason. Just look at the Turkey, they family farm turkey is endangered because it was replaced by mass produced genetically modified turkeys that sell for next to nothing in grocery stores, the farmer can't compete with their prices. So they don't have turkeys, they buy them at the store. Just look online where they sell baby turkeys, most are threatened or endanger of extinction and some are even gone, lost forever because they just are not bred anymore.
Also, just imagine if they passed a law banning the breeding of dogs. Most dogs only live 14-15 years max, so in about 20 years most of the popular breeds would be extinct. There's actually a book about this topic, I haven't read it but it's supposed to be a good read, it's called 'The Invisible Ark'.
https://www.amazon.com/Invisible-Ark.../dp/0978541111
Probably the second reason for breeding ball python morps specifically is that it is a fantastic study in genetics. I didn't know anything about genetics until I started breeding ball pythons, the combinations not only affect the appearance and the offspring but it also affects the physical traits of the snake. For example the Spider gene makes the head wobble to some degree, if you cross a Spider and Spider you get a lethal 'Super Spider'. And the Banana, also known as Coral Glow makes predominately males or females depending on the linage. Some combinations are totally unexpected (allelic for example), i.e. the Highway / Freeway complexes. Both parents / genes are so close to a normal ball python some can't tell them apart from a normal, but pair them up (yellowbelly + asphalt) and you get a stunning looking animal.
Probably the number one reason for breeding ball pythons specifically is that there are so many different morphs out there that are specific non-polymorphic genes that can be clearly defined, more so than any other animal on the planet.