In the wild the line probably would have eventually died out due to the lower production from only the males. Just luck that someone found/hatched it into captivity where the selection pressure is different.

I really haven't been keeping up with all the morphs now days. There is another thread here where someone was picking from two higher end morph/combo females and it occurred to me that I have no idea if either is proven to reproduce. At this point I would assume any new morph could have reproductive issues in one or both sexes until proven otherwise.