Herpin Man

This is the core problem with hybrids. The original breeder may indeed label them accurately and honestly, but "going forward"- what about the buyers when they resell them? And when they are sold again? Or when they are bred with other snakes, how will those offspring be represented? You have no control over that, so of course, you can wash your hands of it, right?
Anyone who sincerely believes that future generations of these snakes will be properly represented as hybrids is deluding themselves.

"I just bought this snake at a show, what kind is it?"
"Looks like a milk snake. Nelson's, maybe?"
"Could be a Sinaloan"
Sound familiar?

There are already lots of hybrids floating around in the herp hobby, and with the possible exception of the first generation hybrids, they are virtually never presented as such. Newer herp keepers cannot reasonably be expected to know the back story on when a given species was bred to another, generations ago, to get a particular gene or trait into that species. Thus, continuing the cycle.
While it is true that these aren't being bred for conservation, I believe that the vast majority of herp hobbyists prefer to at least know what species they actually have, when they incorporate it into their breeding projects. Particularly as it becomes more and more difficult to obtain pure animals from the wild.
Personally, I resent the idea that I am at risk of unknowingly purchasing (and perpetuating) hybrids, simply because, years prior, someone thought it would be cool to breed a milk snake to a corn snake.