a few cahpters in, why does ML always say Mr Kim instead of Mr Beak?

It’s a gag, the majority of the population in Korea has the last name Kim. And so most of the secretary’s also have common last names the most common being Kim, so it’s like no matter who the person was it was always a secretary kim, so now that it’s not a Kim, he’s still like you’re what Kim?

thanks 4 the explanation. :)