Wanting to be called your name and not liking having a person in a superior position arbitrarily rename you as an example of "American hyper individualism". Incredible.

It is literally someone over you stripping you of your own choice of identity.

Even if we removed the idea of teacher/student relationship from this, are you still fine with people just arbitrarily renaming you? That someone respects you so little they won't even respect your own choice in name, that's fine?

I'm absolutely fine with someone who has a name which could be difficult to pronounce in the local language choosing to go with another name. It is their choice. That's the big difference. They're choosing to go by that name in those contexts. It wasn't just arbitrarily chosen for them.