I am also seriously puzzled and don't see the point. Why push to a local remote if the real remote is not reachable? The branch is still not leaving your machine, you are just making a copy of it in another place and now have to manage `local/` refs in addition to `origin/`.

"local" can also be a network fileshare. It could also be in a directory that is treated differently than your other checkouts - whether that's something like deployment, sharing over the web, running CI, etc.