I think part of it is that the phrase is just an obvious affectation. Natural slang, no matter how stupid it might sound, comes with at least some extra ease of use. It's good short hand or expresses something that other commonly used expressions don't. Clap back is just come back with a word nonsensically swapped out.  That, and I've never heard it used in the real world. It seems to sit exclusively with entitled ultra liberals online. And marketing companies.