http://bugs.winehq.org/show_bug.cgi?id=32832
--- Comment #11 from Sergio Callegari scallegari@arces.unibo.it 2013-01-30 13:39:53 CST --- Well, it was not meant for sharing the directory WINEPREFIX among multiple users. It is the typical workaround for the fact that most filesystems (with a few exceptions) do not support per-directory quotas, so that a quota cannot be attached to the WINEPREFIX. Basically you create a group for each directory you want a quota on and you use group quotas.
But I agree it is clumsy and cannot be implemented without the aid of the admin.