To put it another way, I can't think of any real-world disjunctive
dual license involving a (likely) "bad" license other than the Perl
module case (where of course it is really common). If it's so unusual,
why should the guidelines address it at all? Or if the only likely
example is the Perl one, then the guidelines should only use the Perl
(GPL/Artistic) example.

well, as Miroslav began this thread asking about the scenario of having a Good or Bad license (and didn't seem to indicate it was specifically the Perl example - I assumed Fedora packagers are coming across such scenarios

Nope. From me this was completely theoretical question. Just to make the algorithm complete.

The full scan of all spec does not found any such case.

Miroslav