Judging a person's Perl skills by how s/he spells it is overly simplistic.
I'd never judge a person's skills
by how they spell the language.
However, it's a useful clue about how useful they will be to me, which is
a lot more than just their skill from having studied the book.
Most of what I do when I program isn't about remembering the technical things about Perl. It's about finding answers to the things that aren't just
about the language, like is there a module that helps me with this, or how do I link to that library, or can I find a framework to leverage.
For that, you gotta be plugged in to the community, and because of that, you know that it's never spelled "PERL".