Out of curiosity, why do you care so much about other people reproducing?
Part of the point of Eugenics is creating a better organism by restricting horribly poor genes from spreading and trying to get other favorable genes to be more common.
I'm gonna use myself as an example. I have Ehlers Danlos Syndrome (EDS) which is a most-commonly recessive trait that has led to almost all of my health problems, including my encroaching blindness and my inability to engage in much physical activity. I have decided for myself that I'll get a vasectomy and adopt a child, rather than have my own. I do not wish my suffering upon anyone else because of my doing, so I'm going to lengths to prevent that.
Now take a different person, lets call him Chad. He's an average "Chad." He has great physical love appeal, a great metabolism, and has to ability to retain muscle mass for long periods of time. He does not carry a mental or physical impairment, but his family has a history of heart disease. He is of an average intelligence, and leads a normal life with just about every opportunity available to him. The genes of a man like this are some of the most favorable, aside from the history of heart disease, but that is becoming less and less of an issue as medicine improves. He will not suffer the torment of not being able to do what everyone else can, unless he forgets up his back or something, but that's not genetics, that's just luck.
I believe that if we take the time to encourage adoption over childbirth for people with poor physical and mental conditions as a result of genetics, we can create a more perfect humanity. Through selectively breeding crops, we made corn from maize and wheat from grass. Given enough time, we could make gods from men.
I could have possibly worded that better, but I think I got my point across.