If there are some people who get some sort of enjoyment out of reading AI generated stories, then that is all the reason I really need to justify it being there. Though I anticipate that there will always be a market for non-AI generated stories, simply because some people will feel that it isn't real if there isn't some human behind it all.
Though I am amused by the question of how such people would engage with fiction if we reached such levels of computational sophistication that it was impossible for even the most astute of literary critics to tell whether something was written by a human or a computer. Let's say you gave them a piece of fiction and wouldn't tell them whether it was written by an AI. Would they then be unable to enjoy it or engage with it until they had proof that it was actually written by a human? If you told them it was by an AI would they then instinctively find it to be empty and lacking in meaning even if it was written by a human? And conversely, would they find it meaningful, even engaging, if you told them it had been written by a human even if it was written by an AI?
But in answer to your final question, I'd say that doing TLs and creative writing is something we do pretty much purely for own entertainment and amusement.