The problem with a lot of general feminist issues is that there is a lot of agreement, so not much need for discussion. Its difficult for these threads to run for a long time and can be a bit dull with lots of 'i concur'. Or one of the first posters gives good advice, and the thread is useful, but over.
There used to be posts about feminist theory, but they were always long running, slow threads because if we didnt read the book it is difficult to participate. So maybe women read, but not post.
As a result, before trans ideology, the board was quiet and threads didnt get lost. I remember i threads stayed on the first page for weeks.
The trans threads fillied up quicker, and often generated another follow up thread, and then multiple threads concurrently.
So it looked as if trans was stopping discussion about other feminist issues, when really all was happening is that older threads were being pushed down the page, and we'd have to have already posted on it to see it. So i can see why a place for these threads would be useful.
But i remember some feminist theory posters not liking discussion about TRA, they didnt see it as much of an issue. I also remember being shocked how they couldn't argue the TRA case very well while agreeing with it.
TRA obviously didnt like the discussion at all.
So MN had pressure from the women who liked to talk about theory, long established posters who thought the discussion was irrelevant and of course TRA.
The also wanted to move trans threads away from non feminist boards. If they moved AIBU threads to FWR, it would make the matter worse.
The gender board was always going to more active than the 'other' but i think the feminist misjudged the number of women willing to click onto two boards. I often forget that its there, ir assume its quiet without looking.