The problem with "line-bred for color" cichlids, (doesn't matter if its EBJD, or pink oscars, or EB Rams), is that to acquire the heavy desired color "gene" often sacrifices a gene that promotes good health, such as enhancing the immune system, or adaptiveness to things in the environment.
And those weak genes are not easily observed
Especially when the profit motive requires as many individuals in a spawn to survive, and are to be sold as possible.
In nature, in natural color populations, the weak are culled by natural selection (the survival of the fittest) so those that get to breed, are the best of the best, and those have genes that have been harvested from the wild, and are passed along in normal color fish.
Aquarium strains are often not sufficiently culled, are sold before weakness is noticed, so some of those weak individuals that do persist, and because they can sometimes survive in the somewhat protected environment of an aquarium, perpetually breed, and pass on more substandard genes.
Unless the aquarist provides almost sterile, perfect water, its seems albino/pink oscars are more prone to HITH, Rams have shorter lives, and EBJDs have the rep they have.
This scrambling out of "good genes" often seems to occur in hybrids, hence the tendency for FHs to have little resistance to diseases like Columnaris.
