Do people still believe that AIDS is natural.?

I can't speak to what people believe but I can say it is an entirely possible theory that is almost impossible to prove. The problem is that several species have AIDS and nobody knows how or if it has been passed from specie to specie. To figure it out we would need to know a lot more about evolution. It is likely though that a virus designed for disposing of humans would be exclusive to humans, unless of course we weren't yet humans when it was designed.