Personally, I am more concerned with the possibility of conflating and confounding factors. For example, HIV became a thing after we effectively eradicated smallpox. If "AIDS" is really just "IDS" and is not commonly the result of a comminicable disease, then there does not need to be an HIV to explain it. People just have immune systems that fail much like people have kidneys that fail or bone marrow that fails, or hearts that fail. We didn't notice it, before, because it would be the impending doom that a case of smallpox in adulthood was - a sign that your immune system was imploding and you would die from one of the most endemic viral infections in time.
This is not helped by the fact that we do not isolate viruses under electron microscopes anymore. We use a range of methods to try and identify what is in the body that were developed for strictly controlled lab procedures. I'll buy that a gene tag can be detected in laboratory experiments. I'm not so sure I buy efforts to diagnose viral infections in people using these same methods, particularly when we have not isolated a novel virus as an example of the causative agent. In the soup of proteins and synthase products, how do I know we are not picking up debris from cell damage or specific responses from organelles to that damage? If people who are direly ill are likely to trigger a false positive for HIV - what is the common denominator that creates the positive reaction and if a novel virus is not the exclusive cause, what is the probability research is chasing a phantom? Hence all of the magical capabilities of HIV to lay dormant for decades and yet no one has successfully isolated the virus.
I think it more plausible we are looking at some common mode of failure for the immune system which can be a temporary or permanent condition that only has some causal relation to communicable diseases.
Of course… you can't scare the shit out of people and launch insane experiments in africa if it's something so mundane.