@bewitchyourmind I'm sure this was mostly rhetorical, but the reason is related to the fundamental fallacies of radical feminism.

The thing is, many radical feminists on their way to becoming full on SWERF-n-TERFs actually do have a very strong opinion on the roles women are allowed to play. This is why a great many of them loathe any woman who wears makeup or has sex with men, which they tend to refer to as expressions of patriarchy.

Instead, they argue that women should tightly adhere and conform to the opposites of whatever traditional patriarchy says. So, rather than having sex with men, they should have sex with women. Rather than wearing makeup and dresses, they should be barefaced and wear pants. However, this kind of reactionary thinking creates just as tight a "gender role" for women under radical feminism as it does under patriarchy.

Enter trans women: if a trans woman adheres to radical feminism's ideal gender role for women, she is less likely to "pass" as a woman because she will be adopting many traits associated with historical manliness. This creates an opening for radical feminist's to oust her from womanhood by saying she's insufficiently committed to "experiencing patriarchal oppression" by trying to "adopt the identity of a woman without being one."

And if a trans woman adheres to traditionally feminine roles, then (just as with cis women who femme it up), she is a traitor to the sisterhood of radical feminism, and must be ousted from womanhood.

Basically, there is a "win condition" for cis women to be accepted under radical feminism, and that is by being as butch as possible.

But because butch expression tends, on trans women, to be read as "manly" instead of "butch," there is no such win condition for trans women to be seen as acceptable under radical feminism.