"Picking and choosing" is not remotely the same thing as "screening," and that you conflate the two indicates that you either didn't read my comment in good faith or you missed the point by an almost insurmountable margin.
I'd urge you to listen to the needs of your users. You managed to dismiss this out of hand in a way that implies you haven't thought much about women at all. Obviously you don't have to, and you wouldn't be alone there. But this is quite literally a case of a woman giving you feedback about something that many (if not most, by another large margin) women consider vitally important. (The response amongst my group of friends have so far ranged from "unbelievable" to "Jesus Christ.") Do what you want with that information, but don't dismiss it as "wrong" or irrelevant because you believe it applies to all areas of life. You don't have to care about female users, but know that it's obviously a choice.
ETA: in response to the comments below:
1. No one suggested that risk should be completely eliminated, or indeed that this was possible. You're responding to a straw man argument. Which...also doesn't seem in good faith.
2. If you don't understand that someone may screen a group for potential danger without applying further filters ("picking and choosing"), I'm...not sure what else to say except that you obviously have never found yourself in such a position. It seems trivially obvious to me that a user who has already self selected as someone who is looking for a service to match them up with new people would be perfectly capable of deciding to continue in a group after they'd screened it for potential dangers, since that's what they signed up for. People are capable of moderation. In this case, I don't want to be in a group with someone I've seen in a violent situation, and I would rather they hadn't gotten that automatic notification email, either.
This is really very basic stuff.