I can respect the initial opinion, but....many fish bought in the hobby as a given species have been bred in captivity for so long that they're arguably not really the same kind of animals as their "wild" brethren anyway.... and depending on the definition of "species" that you like, many fish that have been in and bred in the hobby are technically already a different species.
Some hybrids are kinda lame, but if it works, it works. While rare in animals, hybrids do happen all over in nature.
If you're trying to be "pure" about everything, you're already hosed, unless you are buying wild caught fish... and as many fish are already endangered, catching wild fish for pets is really and truly unethical to me, much more so than hybrid fish.... as is terminating/killing hybrids, in fear that they may "contaminate" the hobby gene pool. Seems wrong. I don't support intentionally breeding hybrids, but if it happens by accident... and some fry survive... why not?
Remember, dumping a bucketful of captive bred fish into a wild population arguably "contaminates" the wild gene pool.
I still don't like parrots, though.
-Ryan