Probably it's more the former reason. I used to curate my experience on reddit carefully and mainly participate woman centric subreddits, and few male centric ones, and I got used to that. Lemmy looks more like what would happen if you browse default subs on reddit, which tend to be very toxic. It's a chicken and egg problem: you won't attract women unless there are spaces women feel comfortable, and those spaces don't exist unless there are women there to create them.

I still find myself going back to reddit for certain niche fashion or fitness things. And when i try to get my normie girlfriends to look at lemmy, it's hard to sell them on it. They don't care about politics or mod drama and reddit is still better for them.