She's a boring over-privileged youngish woman. Her life is so far removed from the lives of women in the UK it is astonishing she feels entitled to speak for us.
She supports trans demands because she can't imagine herself in a position where she'll ever be negatively impacted by them.
She won't be at her small town bus station at 10PM hovering her privileged posterior over a piss soaked toilet seat, and then navigating her way out of the mixed sex toilet past the local drunk who leers at her tits and mutters something filthy.
She can't see herself in prison having to shower with one of the male prisoners who self-identify as women for the duration of their sentence.
She can't imagine herself as a vulnerable elderly woman in need of assistance in bathing, and after requesting a woman to do the job opening up the door to find her 'female' carer is very obviously male.
If she's ever in a domestically abusive relationship with a man, she has her own wealth to rely on. She won't need to flee with nothing but the clothes on her back to a shelter which to her horror she finds is mixed sex and she's expected to talk about her experiences of sexual abuse in front of a member of the same sex who abused her.
She can't imagine any of these situations so she doesn't see them, and she rejects them. They don't apply to Watson or her privileged life among the global elites and therefore they don't matter.