I hope the strong testing culture and rock-solid reliability are another good sticking point.

CPAN is more than just a repository of modules: it's a tool-chain of software. When you upload a module you get a tonne of feedback about which platforms and versions of Perl the tests fail on, you get reports from CPAN Testers about your library in the wild, and when new Perls come out you get notifications if your library gets broken.

The ability for the language to evolve, I think, has been a big reason why Perl is still around. It's able to adopt new features and simultaneously remain backwards compatible for long periods of time (for the most part).

I don't use perl most of the time, but when I do I like it.