Much much longer discussion, if you want to start talking about the whys and wherefores and etc of the OT. Thing is, it is an old tired argument, whenever anyone wants to justify anything its "well back in the OT they....!!!"
Let's stick to the actual topic. You asked a question framed in religious terms, you got a religious-framed answer. Maybe not the answer you liked, but it is what it is.
The callousness of society... possibly some of it is perception, but it certainly seems like the past 20 years I've heard FAR more stories about mothers killing their own children, attempting to kill their own children, women and men attacking pregnant women and trying to force them to miscarry by beating the abdomen for revenge purposes, that sort of thing. Two decades ago, Peter Singer's advocacy of infanticide up to age 3 would have resulted in him having to leave the country and change his name... now its still a big controversy but he continues to teach "bioethics" at the university.
It does seem to me that society has become more callous towards mothers and children in the past few decades, yes.