I don't understand this mentality. Who told you that you need to own a home to have kids? I don't understand this connection that everyone seems to be making. To me it sounds like an excuse.
You're right that couples could just rent a place and try to get on the proper ladder while trying to raise kids, but realistically I think most would want to do things the other way around. But to your point not owning a home is one of the compromises people who really want kids will be forced to make to have them today.