Re: many packages write to `temporary-file-directory' insecurely

[Richard Stallman]

    > The convention for /var/games is that it is writable for a special group
    > (game) only, and any program wanting to have access to it must be setgid
    > game.

Emacs doesn't need to write in /var/games, it just needs to be able to
write certain specific files that are somewhere under /var/games.
Those files could be created by Emacs installation (which is run as
root) and given modes that allow Emacs to update them.