For the breeder to figure out the proper husbandry for such animals is easier said then done. Yes, we had to learn the proper husbandry for all snakes when they first came into captivity. But when you knew where they come from, you had a lot to go by. You knew climate. You could research about how they live, what they eat, etc.
But how is a breeder to establish the correct husbandry for hatchlings from snakes of different areas and husbandry needs? It is guess work. You could start in the "middle". And if the snake doesn't thrive, you bump up heat. Or lower it. Same with humidity. It could be different for each hatchling. That sounds like quite the job, esp. since one couldn't be sure if the snake is just a stubborn feeder, or actually just being kept in wrong husbandry. I just don't like it. To much guess work and experimenting with only the snakes to suffer for our inexperience. Each time you get it wrong, you don't know if the next step will fix it or make it worse. And RI's are not something quickly cured. I'm sure it goes well many times. And some snakes just adapt to less then ideal husbandry and "live with it". We see that even with "pure breds".