Comment # 3 on bug 971851 from Bernhard Wiedemann

(In reply to Daniel Faust from comment #2)
> That is true, and yes, I know it's bad practice to mix multiple bugs into
> one bug report, but I filed it under "Basesystem" because I think there
> should be a safeguard for misbehaving applications.
> I read a bit more about it (not too much though) and it seems that systemd
> does that sort of thing these days. But it seems to be disabled in
> tumbleweed.

some background info on that:
yes, systemd could cleanup /tmp, but yes, it is disabled by default in openSUSE
because people did not expect it to be on
and lost some files
so it is now left to the sysadmin to enable it,
so that he really knows it is on.