If they had been living in the harsh desert landscape of Rajasthan several centuries later, those women would have been put on the barbeque.
Because in the Subcontinent, resources were not so scarce as in the Arabian peninsula, that is why that practice took place. Even the Chinese Emperors had their concubines buried alive with them when they died. It was because of the same reason that such a practice could take place.
I wasn't suggesting Mohd. did something extraordinary for his own society, let me hasten to add, just something I a) liked and b) "was more progressive than some communities today." I really did not expect that saying women's remarraige is a social good would draw this much discussion, honestly. I think I will quit here.
Which communities would those be? Mostly patriarchal societies were sex is a taboo and men are quite insecure. The vast majority of Islamic societies fit that description....surprise, surprise. They regressed because they followed outdated laws that are not compatible with today's world or the society and culture they live in.
There is not much attention drawn to the fact that he married non virgins simply because it is not important and it was something quite normal in his day and society. No one is discussing anything, we are just highlighting the fact for you.