Why do you think that Allah spoke about those family-members that we can never have nikkah with, in surah nisa? It was because that in the time of ignorance women had no rights. When her husband died, she was married to her son so they could keep the wealth of the father. She was given away to other people, as she was a thing. People had sexual relations with each other without any honour. Males took ownership to women without wanting them for marriage. There was lots of children whom they did not know who was the father of. Then came Islam and gave the male and the female rights and duties. Islam told who muslims where allowed to interact with, who they where allowed to marry, and what kind of matters where permissable and also what matters where forbidden. If it wouldn’t have been for Islam we would have lived in ignorance even today. So Alhamdolillah for Islam.
Roshnii179 