Well in an ideal world, everyone would be eating whole food, not smoking, drinking or doing drugs, there would be no wife beating, violent crime and we'd all live happily ever after.however this is not an ideal world, and people feel motivated to do things for a variety of social reasons. Whilst I'll admit that it's not ideal, and my own wife looks after herself very well whilst pregnant and doesn't smoke when she's not either, I'm not about to decry women and girls whose educational staus I do not know, whose stress levels I can only guess at and who are living eprhaps with difficulties that I am unaware of.
You are of course welcome to bring up your own child as you see fit ( we don't smoke ourselves) but you are coming off as very judgmental and not terribly understanding of what might motivate these women you are discussing.
I'm sure you do a great job as a mother, but there are thousands of excellent mothers who smoke as well, and it's worth remembereing that parenting is more than food or lifestyle, it's also about understanding and unconditional love. Just because someone smokes does not make them a bad parent, just because someone doesn't, it does not make them a good one.