Spiders have what is likely a neurological disorder and I personally will not breed this gene because of it. I agree that the gene is very attractive, but that is not enough for me. If I have to justify its quality of life than I have no interest. This is especially true in animals that it is hard to judge how well they are. Just because an animal attains the basics for life such as breeding, eating, and of course not dying, is it truly living a good life? I am not here to tell people what they should breed, but I definitely think it is ok to think twice about breeding certain traits even if they are well established in the hobby.
Also to the human comparison, I think one of our biggest problems is not being able to look at producing children logically. I agree no one should be able to tell you you shouldn't breed, but I hope as our species moves forward we will be able to self regulate our own breeding for the good of the many. My wife is possibly a carrier for a rare blood disorder, and if there was a chance I was also a carrier than we would just not have children. I hold a similar stance will ball pythons.