I personally find it unethical, and won't buy from a breeder who breeds spiders at all. Not that I plan on ever owning another ball python any time soon. I don't care if it eats, I don't care if it breeds, I don't care how big and strong it gets. Whether or not the wobble affects their health or longevity, I can only imagine the wobble is extremely disorienting. From my understanding, they wobble because their internal balance is off and they feel they're not correctly oriented. Not exactly something I personally consider all that minor, however little it affects the snake's behavior. I have also had several owners tell me their spiders required enclosures with blocked off sides, additional cover, and little to no handling to keep the wobbling to a minimum, as the wobbling seems to heighten during times of stress. I've seen one or two cases where the wobble was so severe the snake couldn't eat. If this can happen, I don't care if it happens often I don't think it should be bred for because the chance to breed individuals who may not thrive, however little that chance is, still exists. Those few cases don't make up much of the spider population, but for me personally I don't really like those odds considering the gene is 100% linked to the pattern and it only varies by degree. It would be a different story if the wobble was able to be separated from the spider gene, but from current research that seems impossible. I'm not going to force anyone else to stop breeding them, but I'm certainly not going to support them with my business.