Hey SisX I think it's awesome that you are engaging with this -- it's important that we do this!
I understand the need and desire to make all women feel included, but again that should be a given. The fact that it's not because of historical trends infuriates me. Of course these women are included because they are women, and their problems are a problem for all of us. Non-straight, white, CIS women, or poor women, don't, in my understanding, necessarily have specialized problems, it's more that the problems all women have are amplified. All women face workplace discrimination, but some more than others. All women fear rape, but some are more likely to experience it than others, etc. Feel free to tell me how I'm wrong about this, though, because it might just be me missing something and I'm open to that possibility.
I definitely can't speak for women of color and other groups, but as someone who grew up quite poor (for America), I can attest to having a different set of a problems as a poor white woman (20 years ago) compared to what I face as a middle-class white woman (nowadays). Like, I can remember being treated like trash by a doctor when I was in school, and quite poor, until he realized that I went to a fancy college. Then he treated me awesome. That kind of thing never happens to me now that I present as middle class.
A few more examples: Sandra Bland faced problems that middle-class white women just don't face. Ever. Women in wheelchairs also face problems that able-bodied women have no idea about. Trans women -- especially trans women of color -- face INCREDIBLE amounts of random persecution and violence that just don't typically enter into a middle-of-the-road white woman's life. Muslim women face discrimination that I would have no way of knowing about unless I seek out their stories, unless I welcome their perspective into mine.
None of the oppressive systems we have operate in a vacuum -- they interact and multiply. None of them exist separate from each other in any way. It's not possible to say, well this bad treatment was because of sexism, this other bit was because of racism, and this other bit because of classism.
Past progressive movements, even when they were successful, still tended to exclude many perspectives. The suffragists ignored black feminists; the anti-war movement oppressed women terribly; the Civil Rights movement largely shut black women out of its leadership. Black Lives Matter is run by black women, who in my experience have the best understanding of how different forms of oppression intersect on individual lives, but even BLM has been criticized for paying more attention to police brutality against black men than black women.
All of this is to say that none of this is simple, but I believe it's worth struggling with, because, to me, the point of feminism is that everyone is basically OK, basically has what they need in this life. If we focus only on specifically what we think of as "women's issues" -- which I would maintain is mostly about "white women's issues" -- then we are leaving a lot of people out of our movement.
It seems counter-intuitive to some, but I truly believe that calling out all the different perspectives of women who face different challenges is the thing that makes our movement MORE inclusive. It's not divisive to say -- welcome, black women! Welcome, Muslim women! Welcome, disabled women, LGBT folks, Asian women, Latinas, everyone. It's not divisive to welcome people by name into the movement to liberate women. It's the opposite of divisive.
ETA:
Must've cross-posted with you, MJ. Happy to follow to another thread if anyone else wants to talk about this more.