In my opinion, if you attempting to make an animal that has a "use", in the case of snakes a "better" pet, hybridization can be a good or a bad thing. They have been making mules for a very long time. At one time the mule was a very useful animal. The problem begins when people loose track of the genetics and don't know what they are selling. That said, if the hybrid can breed, is it really a hybrid? In my opinion it is not but I am not a geneticist. I personally have no desire to try to hybridize ball pythons, they are fine the way they are, but something like a burm hybrid that made them smaller would interest me. I really like them but they are just too big for what I would keep as a pet.