You could be of the opinion that I am a dog in real life.

You would be objectively wrong because I have stated many times in the past that I am a cat in real life.

You may like dogs, you may love dogs, and imagining me as a dog may increase your opinion of me. But I am a cat and I hate dogs and it is insulting to be called a dog.

I have no way of stopping you from calling me a dog beyond letting you know that it's not cool to call cats dogs.

That's an absurd scenario I felt like sharing but if you don't understand how an opinion can be insulting regardless of intent then I think you can at least understand the concept of respecting his wish not to be called an edgelord in public. You are prioritizing your opinion over his comfort and that's not nice.