The UK's 'Women's prize for fiction' is open to anyone who 'identifies' as a woman, as is the Stella Prize in Australia. I'm not sure if this is for political or legal reasons.
These prizes are meant to give women an opportunity to get income and publicity in a male-dominated culture and industry.
Affirmative action literally cannot work for women if males can simply 'identify' themselves into such opportunities.
Why are women being abused for objecting to this? (Currently a trans woman is shortlisted for the UK's prize.) To object to this is not to take an anti-trans stance, but to assert a pro-female stance in an anti-female patriarchy.
These prizes can, of course, do what they like, especially if they are privately funded. But perhaps they should stop promoting themselves as women's prizes. They are, in reality, "non-man-identifying prizes." It would be much clearer and more honest if they simply promoted themselves as such. Is "woman" merely a marketing strategy now?