Women didn’t just come to the battlefield to fight, but also to support the men in various ways.
The issue is, what would you do with the women and children of defeated enemies? If you leave them to fend for themselves, they won’t survive very long and will probably be enslaved by someone else. Looking after them at no cost isn’t very realistic either. So instead they were taken as slaves, which was normal at that time when defeated in battle, and would then have the opportunity of being invited to Islam, integrated into the community and most likely freed within a few years. In the meantime, they were provided with food and shelter, and the possibility of spiritual salvation. Once freed, they had just as good prospects in life as anyone else.
Of course, I’m not saying this was something anyone would welcome, but it was part of life back then, and therefore something that was within the realms of possibility for anyone living at that time. So of course the reaction to it happening to someone wouldn’t be like it would now. The problem we often have when thinking about these issues is we imagine how it would feel for us to be enslaved, but the situations are not comparable. For most of us, being enslaved is completely unthinkable and just about the worst imaginable outcome. So of course something that is not within the realms of what we consider likely to ever happen to us would be more traumatic than something that was quite common.