The problem with this theory, while a good theory, runs on the assumption that the spider gene and whatever causes the wobble are NOT linked.
We have come to assume that the wobble and the spider gene ARE linked. If you don't have the spider gene, you don't have the wobble. If you do have the spider gene, you have the wobble. Thats the facts as we know them right now. I remember hearing on reptile radio i believe it was, that jaguar carpets can have the same problem. They think it may be linked to the reduced melanin production in the body. Melanin or something related to it does some important connecting stuff in the brain, and animals that have less body pigmentation also have less of the "brain stuff." This was just a super interesting theory that I'd heard.
Its not like say... Hip dysplasia in dogs where you can breed animals with good hips together and theoretically get more animals with good hips. ALL SPIDERS WOBBLE, the single original animal wobbles, so do all the offspring.