What’s in a name?

On American TV people at work – any kind of work – call others and each other in person conversation by the last name, usually without a title like “Mr.” or “Ms.”

Sometimes when talking with someone they’ve just met they call that person by the last name with the title, out of politeness, even if introduced with both the first and last names.

I have worked in various places over many years.

I have done a tour in the army.

I have spent years in higher education.

No one talks like that.

Calling each other by first names is the nearly universal rule.

Referring to someone by his untitled last name or calling him that in conversation is considered rude, disparaging, or offensive.

What do you make of that?