There is a reason for disease. As hard as the scientists work to prevent illness and death, the truth is, there is a reason for it. That reason is to prevent the population from over reaching itself. Since we are at the top of the food chain, we have very few predators. Those we do have tend to be trapped into attacking us for their own survival or are our own kind. All that is left to help the earth protect itself from what "Agent Smith" in the movie the Matrix rightly refereed to as a "Virus" are actual viruses.
However we cannot consider AIDS to be a natural way of stabilization unless we begin to look upon all disease that way. This life up until the last one hundred years or so, was always a battle of the fittest. Somewhere along the line, because a mother morned the loss of a child, we all felt bad about one so young dieing so soon and set out to cure all known childhood diseases. Then we set out to keep people from dieing at all. After all, the only thing separating humanity from the Gods is that our bodies are mortal, whether our soul is or not. So we fight to live forever. But, the earth can't hold us all if we live forever.
I have six children. I have that many because birth control failed me. It happens. Fifty years ago, I would have lost at least one of my children. She was born extremely premature. Despite the fact she weighted three and a half pounds, she was born three months to early. She would have died had it not been for the technology we have today. For that matter, I had complications with all of my pregnancies. Many of them, fifty to a hundred years ago would have killed me. But, we see that as sad, not as thinning the herd. Though I added more than my share to this herd, I take comfort in knowing I simply had enough children for myself and my sister combined. She will never have children of her own. That eases my guilt a bit.
Its time, However that we start thinking about changing our thought patterns. Medical science came about because none of us could stand to watch our loved ones suffer. So maybe instead of cures we should be focusing on easing the pain and discomfort of death rather than trying to stop it all together. Maybe then the footprint we leave on this earth wouldn't be such a burden to her after all.