The bashing spider movement is from people who generally know nothing, never owned a spider, never bred them but heard from someone who heard from someone who watch a video once. Sure they wobble to a degree however train wrecks are rare, in most cases it will be hardly noticeable at all and if kept properly a Spider will thrive and do exactly the same things any other BP with any other paint job will do.
Ironically Spiders are the focus of the bashing when other mutations who exhibit the same issue are left aloneif people wanted to be fair their would bash those other mutations as well.
Another irony most people that you will find against the spider gene have no issue with some dogs such as bulldogs, chihuahuas to name a few who have health issues and rarely can give birth naturally.
It's simple you like spider own them, you don't like them don't own them, but saying something should be ban is a slippery slope to ban anything and everything all together because one person disagrees with it.
The majority of breeders are ethical and care and will cull anything that will not have quality of life, in the years I used to work with spiders (I no longer do since I focus on Pied now) I have never had to cull a spider I have however had to cull other animals however that would not have thrive or have a quality of life......that comes with breeding.