Because they always do. See also comments on Russell Brand, Woody Allen, Johnny Depp etc.
They're part of the establishment, and the establishment will always protect men who say outrageously racist, transphobic and misogynistic stuff for cash. No matter how they treat the women in their life.
Jeremy Clarkson's comments about Meghan. James Cleverly's Rohypnol 'jokes'. Graham Linehan being...Graham Linehan. All and many more defended by 'gender critical' women because they're all part of the same club. They're either well-paid by wealthy right-wing media tycoons or close to them - it's fairly obvious.
Transphobia is a tool used by the right to divide the left.
It's been used very successfully to stop all kinds of independence and rights campaigns.
It promotes the idea that male violence is inevitable and can only be ameliorated by avoiding men. It enforces segregation of the sexes, trivialises CSA and says men will always be superior to women. Even at chess and quiz shows.
It encourages regressive 'feminine' stereotypes by policing our appearance.
And does nothing whatsoever to help cis women. Just damages us.