If you could make a case that there would be significantly more pain than happiness, then maybe I could be persuaded.
That depends on what you mean by "significantly more pain".
If you mean that the happiness of eating a cheeseburger or having sex outweights pain of being crushed by a car, raped or whatever, then there is really nothing to argue there.
I simply hold position that not having happiness and not having pain is better than having happiness and having lots of pain.
As long as you hold an assumption that happiness outweights pain in the world, you will end up justifying child birth if you take that for your moral value.
However, the truth is that your position is utterly immoral.
My position: "Everyone should abort", means that I am not causing more pain than I am removing. My position is universal. It would literally prevent suffering of not just humans, but also animals. It also means that I am not causing more pain, therefore not having moral guilt.
Your position could, at best, argue that average happiness outweights average pain. However, even if that was true, it would still be immoral because there are individuals with pain that far outweights their happiness. Therefore, your position would be forced to argue that causing extreme pain to someone is good if it makes someone else happy. So not a very universal position, or even a morally sound one.
