Actually, I do not know what were the intentions of this site creators, so I never considered it.
On the other hand I meet some situations that someone moved to the expired list a code that was actually working, so with the help of comments it was easy to bring it back.
But Yes, generally list of expired codes is pretty useless.
Hovewer this is a huge data cancelation, so I don't feal like I could decide about it by myself. :)