I started learning Perl in 2007; after it was no longer popular, but also around the time that the principles/practices that became 'Modern Perl' were becoming popular in the community.

I think there is a difference between the two though. Java was always a language which required a lot of ceremony and typing to get anything done at all. Perl was always focused on expressivity. Modern Perl was a case of learning from past mistakes and consciously avoiding some of the more egregious code the language easily afforded. Modern Java is more a case of Java playing catch-up to the more expressive languages out there.

One is applying constraints on your coding style, the other is trying to lift constraints. Both are trying to reach some middle point.

But! I agree that no company writes purely 'Modern Perl' - you will have to deal with some terrifying code at some point.

So. I agree with the concept of the 'Modern X' fallacy, but I would say that dealing with non-modern code is pretty normal, and people who are OK putting up with the pre-modern code may be some of your best employees. I suffer from rewrite-it-all syndrome myself sometimes, but it's something I try to avoid. Code that frustrates me, isn't necessarily bad.

(If it helps contextually, I'm - at heart - a Clojure programmer.)