for me, maybe my opposition to continued inbreeding has a lot to do with what i know from other species, and there also is a sense of aesthetics involved.

in nature these pythons evolved over millions of years, and while other species are struggling there still are millions of ball pythons in the wild. their official conservation status is LC, the lowest, it stands for "least concern". and all ball python breeding is still closely connected to that gene pool, even a high-end 5 gene combo still has a whole lot of normals from africa in the ancestry. the outbreeding and recombination and the continued imports keep that connection alive. i think this concept has aesthetic value and will also keep the species strong and resilient.

the issue i have with line-breeding is that you start with a founding population of breeding animals, and then you breed these to each other, homozygoity goes up, you lose the genetic diversity and you lose the connection to the natural gene pool. you may get benefits, like pastels that never ever brown out, or polygenetic traits. but the benefits based on homozygoity are fragile, in that they are lost when you breed it to any other BP. i see how this is going terribly wrong in other species, especially pedigree dog breeding. there is only one way to produce a dog that can be accepted as a cocker spaniel: the parents and grandparents must be accepted cocker spaniels. any outbreeding will mean the animal will not be listed, will be rejected at auctions and shows, and will be labeled "mutt". this is going on for a large number of dog breeds, all isolated. and the result is genetic fragility and an avalanche of serious health problems. i see this as a possible and quite logical consequence of line-breeding: once you get your polygenetic line-bred trait fixed, it seperates from the rest of the gene pool and goes its own ways.

i like how in BP breeding, everything is still connected to everything else, and there is an influx of genes from the wild population in africa. and i dont like how that is not the case for dogs and horses and rabbits and so many of the other animals we domesticated. let alone animals for food production like chicken, pig, cattle. the original horse went extinct and had to be recreated from different breeds, wolves almost went extinct, and i have no clue where to find the original wild ancestor of our modern chickens and cats. BPs, even the most fancy multi-gene combos, still have that connection to nature.

dont get me wrong, i still think that a high inbreeding coefficient will weaken the immune system and make the snake more fragile when it comes to health. i dont have evidence for this in ball pythons specifically, but when you consider all that is known about all sexually reproducing species, you get a picture. but there also are aesthetic reasons for why i like it the way it is. this may be very subjective, but i think it explains the opposition. there is a kind of beauty in the way things are, and i dont see it when i look at a pet bunny or pony or dog.