I did a fair amount of Perl just over a decade ago but can't really see any situation where I'd reach for it over Ruby now. Ruby has Perl's text manipulation goodness with a saner syntax.
Perl was a legit tool in bioinformatics due to its insane text parsing performance. Ruby performance is absolute garbage.
Is anything ever really taken out of /usr/bin once it gets in there? It may be a long long /usr/bin/time.
The rich ecosystem of tested Perl modules for file formats along with the testing frameworks made coping with change bearable - not enjoyable, but bearable.