People do all the time with frogs (especially poison dart frogs) and day geckos. Snakes are solitary animals that don’t like sharing territory with another snake that’s why there was only one python. Once again zoo animals are too valuable to make mistakes with and a lot of research goes into their husbandry. Zoo habitats are becoming more naturalistic and expansive so they can have a small ecosystem in one enclosure that a normal middle class person could never afford, or have the space for.
I guarantee that the retic in that zoo was housed alone and there was not more than one snake per enclosure, on another note there are no zoonotic diseases that pass from amphibian to reptile.