Simple put Mike, there is no reason to house the snakes together, as it isn't beneficial for them; but is more for the keepers benefit.
People argue that they can be found together in the wild, but aside from what people, say, (with out any hard evidence, as ball pythons have NOT been thoroughly researched) something is very true.
They are not social animals, they do not have a social ladder so to speak, or a distinct society involving recognizing other members of a group and relying on them for their mental and physical health.
The only reason people keep them together is because we anthropomorphize them with our fragile emotions and social needs. Snakes are loners, survive alone, and briefly come together to mate once a year. They don't need friends, to cuddle, play or anything we humans like to do.
Ball pythons in general greatly prefer to be in hiding 90% of the time.
Keeping them together can add stress to their lives, which is often enough to weaken their immune system, cause them to refuse food, or for unplanned breedings.
Illnesses are shared, and in rare cases, cannibalism has been documented.
I think keeping any snakes together is a very intense practice suited for those on the professional level, with rigorous indepth experience suited towards zoo keeping or other highly controlled industries.
