Testing. If you share something you've tested and know works, that's way better than sharing a prompt which will generate untested code which then has to be tested. On top of that it seems wasteful to burn inference compute (and $) repeating the same thing when the previous output would be superior anyway.

That said, I do think it would be awesome if including prompts/history in the repos somehow became a thing. Not only would it help people learn and improve, but it would allow tweaking.

To save time and energy?