If this were a signpost along the lines of "employees must wash hands", then there would be no problem. Of course employees should wash their hands.

The problem is the weaponization against random people for obscure reasons. The blog poster here didn't make a presentation full of racist jokes, it's not even clear what they did.

Lawful evil anti-social people exist in the world, we shouldn't let them bully people just because they're waving a rainbow flag while doing so.