Juthunter28: As a bio major I can ask you: what the are you talking about? That was gibberish; I understand the words, but not how you put them together.
There is a difference between genetic variation inside a species and then genetic variation between species. No matter what, individuals inside a species are genetically more similar to each other than anything else, even considering the SLIM chance of mutation during meiosis (more accurately it would probably be during DNA replication and translation, in errors in one of those mechanisms). That's why they are species; that's how taxonmy works. Individual B. splendens all have different genes. But they're all splenden genes (one would hope - again I've read [single source] that domestic bettas are mongrels, which is quite discouraging and why fish keepers don't like hybrids).
You said every species individual is unique or something such (to say that everything is a hybrid). I think hybrids can cause problems because you don't have a defined species; the parental DNA can do different things in different individuals. In the wild, on the off chance a small number of hybrids occur, the enviornment will kill them all off or, at best, start causing the genetically similar/superior individuals to survive and breed. This doesn't happen in the aquarium, so its impossible to keep these fish categorize uniform species.
Hybrids aren't a new species. They usually don't breed true, thus, not a species. Rarely, (especially with complex organisms, more often with plants) hybrids can occur, begin to breed with each other and establish a species, where the enviornment generally forces genetic similarity (read, similarity, not uniformity). But that's not the normal course of things. It doesn't happen so often that you can say every species is a hybrid. Almost always given the chance animals will breed with their own species. Rarely does hybridization occur (especially in higher organisms - plants can wind or bug pollinate), and when it does, rarely does it occur so much that a population can become established.
I've never had a punnett square where an organism was "corrupt" and died. I've done a few with genetic disorders, but nothing about corruption and dying...perhaps you can enlighten me before I have to take the class?
The problem with fish like that is even after generations it's not a purebreed for whatever species it resembles (if it is even viable and resembles one of the parent species). It can still hide genes that will go on to its descendants. That dillutes the purebreed species gene pool. Not good.