You are not actually saying that she regretted having you, only that at the time she would have killed you if she could. It's obviously a horrible thing to say, to even feel, but it's different from what we are discussing.
Let me make it clear - she regretted having me. Those are the cold hard facts. If she could have aborted me and had another child later when she was prepared to have that child then she may have loved that child. As it is, there's a very dark downside to forcing unwanted children into this world that isn't being discussed.
Nor can you project your naive thoughts of rainbows and unicorn farts on everyone living in Hell. It's extremely offensive. This is why nobody talks about it - tone deaf people like you trying to pooh pooh people's experiences and what they've watched their friends experience. Sorry. We're fighting back.
And I'm not doing that. I don't doubt that you had a rough childhood, your mother is clearly an unfit parent. I still maintain that preemptively killing children because they might end up in bad families is not the way to go. A working social safety net, adoption, financial support for those in need are the humane way to solve it.