Moving parts in rubbing contact require lubrication to avoid excessive wear.

Honorifics and formal politeness provide lubrication where people rub together.

Often the very young, the untraveled, the naice, the unsophisticated deplore these formalies as 'empty', 'meaningless', or 'dishonest' and scorn to use them.

No matter how 'pure' their motives, they thereby throw sand into machinery that does not work too well at best.

--Sam Spade