“how did people think it was okay to kill babies that inconvenience them?”.

Let me fix this for you.

"How did we create a society with so little support for mothers that some had abortions for financial or lack-of-support reasons?"

That's the real tragedy. If a woman doesn't want a baby, then she's going to be a horrible mom and raise a horrible person. Those people can have abortions all day and night for all I care. But the women who might want one, but can't afford it, but don't feel safe in their own home, that's society failing.