Well, I guess we're asians just love using indirect approach in conversations. I don't live in Japan, it's not as rigid here as it is in Japan. But even at where I'm from, we like to call someone by their family name in formal settings, or if we aren't really close with that person.
I guess for you westerners, imagine it this way... Which is the most polite. Mr. President, President Trump, Mr. Trump, or Donald.