Even when you have a neice or nephew without a parent, and the choice is between you taking them in, or the state?

Yes. It's still a choice, even if you think the alternative is unacceptable.

Or when you do everything right, but your protection fails?

Or when your ex wouldn't accept the word "no"?

Absolutely and especially then. Abortion is an option.

Hell, it's not even a remotely exhaustive list - there's a lot of ways where raising a kid is the responsible choice, even when you didn't want to

It's never the responsible choice to force a child to be raised by someone who didn't want to raise kids. Not ever, not even a little bit.