I personally think it's unethical. Most arguments for spider gene animals and other wobblers are about how good they are for the industry, for breeders and morph enthusiasts. That really doesn't sit well with me. These are living things that we're creating, and people choose to make them with neurological disorders just because they're pretty and sell well.
I'm always amazed at how certain some people are that the wobble doesn't affect quality of life. I just... Look at them. The bad wobblers really really seem to be in distress to me. Not necessarily physical pain, but I imagine it would be very upsetting to intermittently lose control of your movements. They look so frustrated when they're corkscrewing.
In any case, despite individual feelings/perspectives on quality of life in spiders, the truth is that we cannot know for sure how they feel or whether they *suffer* from wobble, nor can we tell to what extent it bothers them. So, at the end of the day it's up to each breeder to decide whether they think the risk of suffering is worth it or not.