I don't know if it's "poor" genetics, but perhaps a mutated gene. Just a different color variant that has been selectively bred in captivity. It's likely that in the wild the white Dempsey would be at a disadvantage because it would stand out and not be able to use its normal adaptations (dark color, etc.) to hide from larger fish when it is young. Thus, not making it to adulthood and being able to reproduce and pass on that gene. Similarly, like white lions, white tigers and even white alligators who suffer from some type of (leucism - a condition in animals characterized by reduced
pigmentation. Unlike
albinism, it is caused by a reduction in all types of skin pigment, not just
melanin.) most animals with this condition are almost only seen in captivity as I had stated. Surviving in the wild is already tough when you are born normal, but this difficulty is compounded in the survival of the fittest, especially when you have to rely on being inconspicuous at times(hunting), and not seem odd to the opposite sex(mating), and of course make it to adulthood by not sticking out like a sore thumb when you are young and vulnerable. If I was into buying normal brown lions and such, and came a across a white lion for the first time...poor genetics or not, I would buy it because it was different. Same reason I bought the Jack Demspey, it was different. And it wasn't a penny more than the "normal" Jack Demspeys, which by the way are almost surely inbred by breeders and also of poor genetics. Unless of course they are wild caught or come from different family lines. Either way, here is a link for a guy who was crossing these white Dempseys with the Electric Blues. Interestng read-
http://www.monsterfishkeepers.com/forums/showthread.php?327353-Gold-JAck-Dempsey