They've been conditioned to respond to certain key phrases with certain responses.

So the trigger goes trans women -> care -> women's sports but you don't get women's sports -> care.

Or veganism -> care -> nutrition but not nutrition -> care.

Our brains are weird things, they have to develop links between ideas in both directions or else they stay one-way. It takes real work and discipline to develop critical thinking practices, and even then you have to keep working at it to minimise this kind of cognitive dissonance, and you'll never get rid of it entirely.

Of course it helps if you're not miseducated by authoritarian schooling practices and conservative media.

Or how people care soooo much about babies lives until they leave the uterus . After that, they can go die for all they care.