There may be an enviromental factor that coincides with a genetic pre-disposition that can agrevate the underlying genetic disease. There are two enviromental factors that have in the past been considered a contributor to causing the disease to progress. Overfeeding and allowing the use of stairs when the animals are still growing. The latter usually was only a factor in large breeds like Mastiffs.
All effort should be taken to avoid breeding animals who are known to have the issue since you cannot say for sure how much of it was caused by poor genetics and how much was caused by enviroment. Sometimes this cannot be avoided as dogs may not show the disease until after they have already had offspring. So in some sense it is not entirely avoidable. But one should try.
I do not have a problem with people breeding spyders. I accept the testimony of those who have when they say the snake does not suffer for it.
However....
Do we know that there are no long term, linked affects of snakes that have the wobble? Could some other disease manifest itself that would affect the snakes longevity? How long before we know the long term affects of this genetic defect? Can we make any definitive conclusions without studying the snakes for their entire life cycle?
Do we even know what the wobble is? Is it neurological? Is it a muscle defect? Combo of both?