the word itself is probably a 4chan thing, if I were to bet anything. but it's normalization may have been a weird twitter thing
@SuricrasiaOnline I've heard rumors that the word "shitposting" came from SA, but they used it to mean "making really bad posts in a thread to derail or tank it"
the mastodon instance at cybre.space is retired
see the end-of-life plan for details: https://cybre.space/~chr/cybre-space-eol