I think it is a shame that fish are bred out hybrids, and you have to rely on wildcaught fish (which is never really that good a thing). Maybe you've been looking in the wrong places for captive bred purebreeds, or simply there aren't enough of them.
As much as in a very very slight aspect and at a different angle i agree with some of what you say, but i'm sure as YOU have started a thread people are gunna go "damn that dudes right, i'm gunna go kill my prized flowerhorn" or whatever hybrid fish. It simply won't happen. It's cool your into purebreeds, which i'm a big fan of, but there will always be people happy to buy intentionally, or sell intentionally hybrids, for their own enjoyment, or their pocket.