This is an example of the "Euphemism Treadmill." Words that refer to things that some portion of society hold negative views about acquire negative connotations over time. These words are then discarded by polite society for clean new words without the baggage. E.g. latrine to water closet to toilet to bathroom to restroom, or retarded to mentally handicapped to developmentally disabled. See: https://aeon.co/essays/euphemisms-are-like-underwear-best-ch...