I suppose it's possible that there are good parents and children who don't suffer, but honestly I really do think the majority of all children in the world are subjected to abusive, neglectful, or inadequate upbringings that scar them for life. Parenting should be STRICTLY regulated.
The idea of regulating parenting sounds like a good one at first glance, but after having a debate about this on other sites in the past, I've come to realize that it might not be as good of an idea as I originally thought. The first problem is: Who is going to regulate this? If it's the government, then it's likely that the personal biases of the politicians involved will be the deciding factor in who can have children. People could be denied the privilege of having children because of their religious beliefs, ethnicity, political ideas, or any other reason that the government arbitrarily decides on, even though the people who are denied could have been excellent parents. If they can't be counted on to regulate it, then who else could do it?
The second problem is that there is no guarantee that the regulations will prevent abuse from happening. Some parents could qualify for the privilege of having children, but could still be abusive in ways that don't violate the rules. The third problem would be deciding who is able to qualify, even if the biases of the regulators weren't a problem. They would have to evaluate whether or not a person applying for parenthood is likely to be abusive and if the applicants are knowledgeable enough, they could find a way to cheat the system, obtain their license (if they need licenses to begin with), and then proceed to becoming a horrible parent anyway. Narcissists would probably be the best at accomplishing this goal. There would also be the problem of dealing with those who've either managed to cheat the system or found a way to procreate without being detected. What if unlicensed individuals manage to escape detection and provide a good life for their kids, only to be discovered later on? If that happens, law enforcement would have to take the children away from their unlicensed parents, but doing so would traumatize them, which is the very thing that the regulations are supposed to prevent. As for the parents that are able to cheat the system, the second problem is likely going to be involved here because they could find ways to either hide the abuse or use a loophole to avoid legal consequences by abusing their kids in a way that isn't forbidden (for example, sexual abuse and physical abuse could be defined as abusive behavior, but emotional abuse might not, therefore they could get away with it, but the children would still be miserable).
@Heavy to answer your question, I hate people who decide to have children for completely stupid or selfish reasons, which seem to be the most common reasons for having children, but I don't feel the same way for people who have selfless or intelligent reasons. I just think it would be unfortunate if their kids failed to accomplish whatever positive goal they were hoping to achieve because it would have been a waste of time and energy, especially if they became suicidal one day. I honestly think that it would be better if no one had kids, ever, because that would prevent future generations from suffering in this hellhole that we call Earth. It's the reason that I will never be a father. I would never be able to forgive myself if I changed my mind about that, only to have my kids become depressed and suicidal like me. The mere possibility of that is the reason that my mind cannot be changed about this.