I understand that the author's point is that we should replace "first name" with "given name(s)" and "last name" with "family name(s)" if we are going to have t

I understand that the author's point is that we should replace "first name" with "given name(s)" and "last name" with "family name(s)" if we are going to have two fields instead of just one for the full name. It's true that it would be more clear in some cases, since in many cultures the "first name" is the family name, which is probably not what the system expects. Though I do agree that it's mostly a matter of i18n. In Spanish you should ask for "nombre" (name) and "apellido(s)" (surname), if you say "given name" and "family name" users will be confused.