Every time the "spider issue" comes up, someone wants to make the comparison back to bad dog breeding habits. While I get the point trying to be made - and have considered it myself in the past - I'm not sure I can bring myself to take it seriously.
Defects in dogs bring about known, painful, and life-shortening harm to the animal. I have German Shepherds, and the amount of people that buy a dog without getting their lineages checked for hip problems is astounding. A dog like a GSD needs interaction and exercise and stimulation, and it's easy to make the argument that one born with hip defects will not live a fulfilling life, especially if that life-span is drastically shortened.
The same can't be said for a snake. We keep these animals in small, contained cages. They do not require interaction or stimulation beyond being fed regularly. Most of the time they're curled up in one spot. They live the same amount of time another snake would. Their lives are not shortened, their interaction is not changed, they eat, they poop, they live their lives as any other snake would.
I'm just not buying it. If there's a better comparison out there, I'm all for hearing it. But being that snakes require so little in the way of care and interaction is most likely why we don't see the same stipulations and lineage tracking as we do around dogs. I'm not sure we ever will... and the "spider issue" is going to be left to personal preference and opinion.