Comparison to Western Culture: In English, we might add politeness with phrases like “Excuse me,” or “May I ask,” but the noun “name” itself remains neutral.
大名 changes the noun itself to be honorific. It's a level of built-in respect that doesn't have a direct one-word equivalent in English. Using
大名 is a way of giving the other person
面子 (miànzi), or “face,” by acknowledging their importance.