This is a misunderstanding of the point.
Certain feminist think that the women's movement is a leftist political program, that wanting to protect women and their rights means being on the left. They typically believe that any belief system that is not leftist is oppressive and wants to dominate women (among other people.)
They also believe that feminist organizations should set the agenda for policy on women's rights and can claim to represent women's interests.
The problem is - there are lots of conservative women, who don't agree with what these leaders of the women's movement say about what is best for women, what policies government should follow, etc.
But more saliently here, they don't like the implication that they are somehow outside of an interest in, or input around, women's issues, because they don't see those within the frameworks of either Marxism or identity politics or other leftist paradigms.
They very much feel like this group of women are the ones trying to dominate them and delegitimize their views as "anti-woman" while claiming only their own views are pro-woman. And this is seen as basically self-evident.
There is a similar dynamic in a lot of race identity politics, self-appointed leaders who want to represent the group in public discourse - but I think it's the worst within feminism.