I get what you're trying to say but I don't totally agree with you. On a simple biological level the gene causes a neurological problem. The gene itself is not defect but it causes a defect (meaning something isn't working the way it's supposed to). That's literally all there is to it. I already refrained from calling it a genetic disorder cause I think the term is too harsh. I know that these animals can live and breed without problems but there are cases in which I wouldn't take it upon myself to judge the animal's quality of life (for example when they start corkscrewing). In fact I don't know how much the gene affects the animal's quality of life but I can only say what I see and so can you. From what I see with my pet, I doubt it affects him that much. I never said they're unfit for ownership. As I stated, I have a ball python with the spider gene as well.
And yes an albino is also a different gene which technically causes a defect as well. If I would have thought that people didn't know about that I would've said that as well. And again when it comes to breeding I think it's too easy to either say I'm against it or I agree with.
Keep in mind that just because something can be bred it doesn't have to be bred. Pugs (the dog breed) for the example are poor little things. They are bred in a way that they can't breath properly and most of them faint from time to time. But some breeders just recently have started to tryi to breed in a way that they can breath better.
So do I think ball pythons with the spider gene should be bred? I don't know because I don't know how much that condition affects them and that's also the reason why I wouldn't do it but others can do it if they think otherwise. I just don't think that it's a certain yes or no.