The number I was able to find is 13%. Only about 13% of men lose their ability to reproduce before they die. Even with a weakened sperm they can get women pregnant at any age. As for the man's dream. Well the thing is technology is going to make that available to all men. Every man will be able to have a harem if he so pleases. It is just a matter of time. Actually you could make the argument that men are already having their dream come true. You can have your own virtual "castle" of your liking and you can populate it in any way you want right now in multiple videogames. I did something similar in a modded version of Skyrim about 6 or 7 years ago. This will only get more and more potent when VR technology and robotics became more available in the coming years. From what I gather the more I look into this subject is that humans are not mature enough to be able to handle the control over their own sexuality.

But we have already taken nature out of the equation. We are not going to go back into being small groups of hunter / gatherers again just to allow nature to take it's course.

I am afraid that the only way across is through...