I wouldn't go so far as to call their comments dehumanizing. Rude and uncalled for - absolutely. But no part of their comment proclaims that the other person doesn't deserve basic human rights.

Right to be recognized by the identity you give to the world. Respectfully, we disagree.

Indeed we do. I was approaching human rights from the perspective of having a right to food, clean water and shelter, and not being threatened for your life every day. Having other people talk to you/about you the way you'd want somehow pales in comparison.

Dehumanization is the result of treating a human like they do not have equal rights and dignities.

If we decide that identity is a right within someone's control, that decision must be consistent.

If I call you "Steve," and you correct me and say, "no my name is Bob," you have exercised what I see as your right of domain over your own identity.

To preempt that right and respond with, "I prefer to call you Steve," would be absurd and rude. Also pointless. It would flout any right you have to decide who you are.

To do this in an argument or confrontation easily results in dehumanization, merely by suggesting that one person is allowed to determine their own identity while another is not.

Even if we relax this discussion to non-terminal impacts, it is quite literally optimal to just allow people this dignity.

The energy it takes to enforce every definition as your own is unsustainable. If two people cannot agree on basic definitions, there is no chance for valuable discussion anyway.

The most basic definition that exists in an argument is the parties involved. Disagreeing on that basis invalidates everything downstream.

So--if one is arguing in good faith, it costs almost nothing, and you gain a lot, to simply allow the other party to define themselves.

It might for you. That would be a myopic view of the world and of dehumanization by nearly any widely accepted definition.