Strategically Gay

I have another hypothesis. It goes like this: I believe that homo-sexuality is advantageous to the human race. At least it was up until the latter half of the last century. This hypothesis is solely a species related advantage and has nothing to do with any cultural aspects of being gay.
Here's how I figure it. Throughout history, I believe that a certain percentage of the human population has been homo-sexual. As population increases, the number of homo-sexual individuals, both male and female, have increased but the percentage from the whole population has stayed the same. So if 5% of the population is always gay, that stays the same but the overall number of homo-sexuals increases with population increase.
I belive there is a reason for this. I think that the human species has built in mechanisms to slow its own growth. If a percentange of the population is homo-sexual and therefore can not procreate, the population can in theory stay in check before outside forces such as pestilence, hunger, poverty and natural disasters destroy them instead. However, being as smart as the human species are, we have found a way around that little issue with the invention of in vitro fertilization. This way any gay male can have his sperm put into a female or any gay female can have sperm inserted into them. Gay people having children, Voila!
An advantage no more.