I think you're misunderstanding the point of a circlejerk sub. It's not /r/books2, it's a parody and mockery of /r/books. The jokes about audiobooks are there because there's a huge trend in /r/books of making these big dumb dramatic posts about how audiobooks are literally exactly the same as paper books and there's no difference in the experience whatsoever and all you ELITISTS need to shut up about how audiobooks are bad (made in response to exactly 0 people talking shit about audiobooks), so the circlejerk sub makes fun of that.
I think you're misunderstanding the point of a circlejerk sub. It's not /r/books2, it's a parody and mockery of /r/books. The jokes about audiobooks are there because there's a huge trend in /r/books of making these big dumb dramatic posts about how audiobooks are literally exactly the same as paper books and there's no difference in the experience whatsoever and all you ELITISTS need to shut up about how audiobooks are bad (made in response to exactly 0 people talking shit about audiobooks), so the circlejerk sub makes fun of that.