I think the fastest way to convince yourself that Perl is obsolete is to try to hire for good Perl programmers. It's a fine language if you treat it well, but it's going the way of COBOL.
Module growth is strong, and accelerating.
Not quite the hallmarks of something going the way of COBOL.
Note also that Fortran is also in heavy use in various science fields. Rumors of its impending death have also been greatly exaggerated.
Hire for good programmers, and they'll be good Perl programmers if they need to be.
Yeah, sure, hire a Ruby/Python programmer ... and try to trick them about the language they're going to be using by being vague about it in the job posting and initial conversations until they got really interested?
Been there, done that. It was a stopgap measure that sort of worked and it wasn't that much fun.