This isn't a bunch of schoolchildren inventing new words or some literary movement to change the spelling of a class of words. This is one mistake by a dude who wrote something years ago that now everyone has to duplicate. It is a terrible example of "living language".
Is it? When I'm writing about somebody who refers another person somewhere, I use "referrer." When I write about HTTP headers, I use "referer," even outside of code (i.e. in chat or prose). They're distinct concepts that now have distinct (but homophonic) words.
