For me, this is an issue of intersectionality of oppression. That's a concept that I think is often misunderstood and one which imho, radical feminist thinkers are unwilling or unable to engage with fully. It's not just that a woman experiences "sexist oppression with added racist oppression," if she is a woman of colour, but her experience of oppression as a Black woman will be something different from the experience of oppression of a white woman or a Black man.
Intersectionality is also predicated on the understanding that the same person can experience oppression because of one part of their identity and privilege because of another part. There is no formula for working out top or bottom of the league tables and absolutely no point in trying to do it, although alot of people DO seem to waste a helluva lot of energy in trying to do so.
I have seen in discussions here and elsewhere the insistence by radical feminists that patriarchal oppression is the root of all other forms of oppression and/or that misogynistic oppression effectively trumps all other forms of oppression. However you slice it, that suggests a belief that misogyny is inherently "worse" than racism, homophobia, class oppression, etc. There seems to be the idea that once patriarchal hegemony is smashed, there will be no more racism or homophobia or classism, because all these forms of oppression stem from the patriarchy. Back in the early 80's, I was told the same thing by a Socialist Workers' Party mate - that once the class struggle was won, there would be no sexism, racism, heterosexism anymore because these were all predicated on class-based oppression.
So, here's the point. Trans women challenge those of us who were identified as female and have remained so all our lives to acknowledge not just the oppression we experience as women, but the privilege we enjoy as not being trans. As I've mentioned before, it's not the first time in history that feminists have resisted the idea that they are privileged, for example, due to ethnicity if they are white or class/economic privilege if they are not working class and/or educated. This has been and remains a painful issue for many women of colour and working class women who still feel they aren't necessarily "heard" or their specific struggles acknowledged within feminism of any type.
IMHO, lack of acknowledgement of the intersectional experience of oppression perhaps comes from fear - fear that if you acknowledge you have privilege, it will somehow dampen or negate understanding of the oppression you experience. In some cases, folks will go to extraordinary lengths to avoid "owning" their privilege. We can all think of scores of examples I'm sure of men who use all sorts of contorted explanations, "scientific" evidence, subject changing, anecdata, personal pops and flat denial to avoid owning their male privilege.
And, on that note, kim asked above whether people here believe trans people exist. In my view, I don't believe the radical feminists who organised and support the policy of the conference in question do. They have invested everything in the idea that there are males and females but nothing in between. The former benefit from oppression of the latter. Introducing the idea that there are people who aren't just male or just female jeopardises this central concept, so can in no circumstances be countenanced. Therefore, if you are identified as male from birth, nothing you do, nothing at all will make you anything but male, will make you anything but a person within the group defined as oppressors of women. To "prove" that point, they will use contorted explanations, "scientific" evidence, subject-changing, anectdata, personal pops and flat denial.
I'm seeing lots of them on this thread, along with quite alot of high fiving and back slapping, strangely reminiscent of comments from male contributors to The Guardian CiF section, when trying to rubbish articles with even a slight feminist theme and take down their authors, particularly if female. Depressing there. Depressing here.
Encouraging though that pretty well all the real world feminists I know and collaborate with aren't this prescriptive in their understanding, thankfully. Time to leave the mouse and get on with making a difference! Ciao all.