I happen to agree in this principle, but for most of human history it would have been considered a radical idea. Much of the world still doesn't fully buy into it. It's a philosophical position, not a universal truth. You need to persuade, not force. Banning people is not the answer, provided they are communicating in good faith.

> If someone’s opinion is that not all human lives have equal value, then yes it does make them awful.

FWIW, it’s a little more nuanced.

Do all human lives have equal intrinsic moral worth? Many, though not all ethical systems say yes. I think this is the case you’re thinking of.

Are all lives valued equally in decisions, emotions, or outcomes?

If all lives are truly equal, how do we justify medical triage? War? Immigration limits? Prioritizing children over the elderly? Choosing to save your family over strangers?

If lives are not equal, on what basis do we rank them without sliding into cruelty or abuse?

There’s no fully stable resolution to this tension and every society lives with it.