It's hard to answer why 50 and why women as separate questions because it's really the confluence of age and gender that makes our problem statement unique. We did a lot of user research with women of this age. We heard a consistent story: as she ages, she feels more and more invisible to society. Women with grey hair become less powerful; men tend to become more so. At the same time, though, she herself is feeling stronger and more comfortable in her own skin and "gives less f" than she ever has before. And so our goal in building Revel is to build a space where we can celebrate the power and strength that comes from being a woman of this age.

Seems like older men wouldn't be interested in hanging out with other men, let alone "hosting" events.

Source: a few years short of the target range. I only have a few male friends, made 15-20+ years ago. In contrast, my wife goes to all sorts of female-only gatherings pretty much every week. Nominally they "paint" or "craft" something there, but I'm pretty sure she just goes there for the social environment and to talk.

Seems to me a service like this isn't really possible for older men, at least not in any of the countries where I lived.

the restrictions are the entire point of the system. they could have picked any discriminators, but described why they wanted these filters on their community in the post.