Kind of like asking why anyone would own venomous snakes, green tree pythons, amazon tree boas, emerald tree boas, and many other snake species. I also have a green tree python who is not really handle-able.
She's a rather uncommon species, is fun to feed, fun to watch, fun to keep, and fun to take her out for videos as long as she doesn't bite me in the face. Sometimes snake keeping isn't about getting another puppy dog to sit in your lap and do nothing.