@icekatze Yah, but lots of people who think they won't be good parents would be better than they think.
Of course, what society expects from being a good parent would be different. In certain parts of the world, if a parent spends more time with their kids where other families don't, it often bothers the child. But in a place where parents regularly spend time with their kids, it'd bother the child to not get that attention.
But a huge point that is different from modern times to times of the past really is time.
My great grandparents needed to make many children because there was no guarantee that all of them would survive and they might not have descendants to carry their family name/legacy (and it wasn't lack of food or money; though it wasn't a rich village. But random diseases or accidents that, at the time, they couldn't guarantee to heal could kill their child). In their village, everyone had many children. My grandpa had over 10 siblings (and he was the last one to die). My grandmother also had more than 10 (I don't know how many exactly).
During my grandparent's era, the survival rate of children drastically improved and people were fine with 4-5 children (maybe even less); but the world wars kinda scared them too during that era.
There was a certain desperation they would have that in modern times, we wouldn't have. Modern medicine can help with so many problems that they couldn't deal with before.