I kinda can't beleive we're having this discourse, but nobody thinks we should get people fired for latent, unspoken transphobia. How would anyone even know?

What they want is to get transphobes removed from workplaces when they make those places unsafe for trans people.

This isn't punitive, it's to protect a vulnerable minority group. It is to keep this attitudes out of institutions where they can cause real, material harm.

The same way that it would be unreasonable to suggest firing every man with unconscious sexist attitudes (literally all of them), but reasonable to suggest to fire the ones who are outwardly sexist in the workplace.