> argument is that they had actual systematic power
That's the sort of ephemeral power I mention, and that's the kind of claim that requires both evidence and specificity. Do people have that power because of a given trait (their gender, their skin, their nationality), or do they have it by being "the majority"? Does this apply to all majorities? If men of Asian descent are the majority in your field, should you react by having non-Asian focused groups?
> minorities within a given sphere often lack actual power because their specific needs go overlooked.
Do minorities have fundamentally different needs? Sure in your case of someone who is wheelchair bound that applies, but that doesn't seem to apply to say Brown-eyed software developers (to intentionally choose a non-combustible example).
> Would you join a wheelchair users group and ask for a stairs advocacy subcommittee in the name of equality?
I don't have an issue with exclusive groups. I have an issue when only some people are allowed to form them. If someone wants to form a stair -championing group, they should be able - even though it's silly. The people who prefer stairs and the people who are unable to use them both have fundamental rights to organize.