Isn't it odd?
Everything in modern society is heavily regulated: You need a permission to build a house or to drive a car, there are noise regulations that prohibit you from doing what you want on your own property, yet every goon can (and does) procreate. If you timidly propose that some regulation, however slight, might be in order, you will be branded an eugenicist in an outcry of outrage.
Somehow, demanding that something as serious as creating a new human being is held to a certain standard seems to cross a line.
Apparently everyone is entitled to offspring, but not to housing, food, health service or other vital resources that are essential for every human being once it exists.
Why?
Housing, food, health service etc. require money, whereas everyone can make a child for free. Hence, many people don't oppose mindless procreation, since it doesn't cost them; only when the child thus conceived begins to make demands does it becomes a nuisance.
Luckily, most people in modern society have erected a wall of ignorance which prevents them from being bothered by other people's problems, even if these might have negative consequences for themselves in the future.
What about abusive and mentally ill parents?
"Well, that's not my problem!" they say, until it is and the child becomes a criminal, a homeless or simply a society dropout.
Luckily, these aren't real problems:
Criminals will rot in prison, irrespective of the circumstances getting them there; what's the point of investing in people early in life if you can simply punish them once things take a wrong turn later on?
As long as the homeless don't hang out in your favourite park, they are of no bother, and if the society dropout doesn't use up too many resources, he can be easily ignored as well.
Either way, if people don't like the life they have been gifted, they can simply kill themselves; it's that simple!
It is far more important to preserve the essential right of procreation; God forbid that the human race might go extinct!
Von Linné revealed a delicious sense of humour in branding humans "homo sapiens sapiens".
[I apologise for this diatribe, but any kind of child abuse makes me extremely angry.]