If you're not sure what sort of $foo is silly enough to advocate, take a look at the languages at the Turing Tar pit. Plenty of languages there which could well be better than perl.
As C++ templates are Turing complete in themselves, advocate why they are
better than perl. C++ itself probably has enough advocates already, and
doesn't need our help. sendmail configuration scripts, xslt, Conway's
Game of Life and (obviously) Turing machines are also both Turing complete but
no-one sane would suggest them instead of perl, so now is your chance. How
about z-code, dd/sh, Postscript, FORTRAN, COBOL, BCPL, Acme::Inline::PERL and
perl1?
I don't think that Babbage's difference engine is Turing complete, but it doesn't stop it being better than perl for calculating logarithms to many decimal places. Likewise the Bombe was much better than perl at breaking the Enigma cipher. And just being good at one niche doesn't seem to stop other people writing unqualified $foo is better than perl discourses, so write one for us.
Anything else that is not advocated as general purpose computer languages is probably also a fine candidate for a spoof.