People who refer to it in all-caps instantly give themselves away as outsiders to the language.

It's actually laid out in perlfaq1 ($ perldoc perlfaq1)

   What's the difference between "perl" and "Perl"?
       One bit. Oh, you weren't talking ASCII? :-) Larry now uses "Perl" to
       signify the language proper and "perl" the implementation of it, i.e.
       the current interpreter. Hence Tom's quip that "Nothing but perl can
       parse Perl."

       Before the first edition of Programming perl, people commonly referred
       to the language as "perl", and its name appeared that way in the title
       because it referred to the interpreter. In the book, Randal Schwartz
       capitalised the language's name to make it stand out better when
       typeset. This convention was adopted by the community, and the second
       edition became Programming Perl, using the capitalized version of the
       name to refer to the language.

       You may or may not choose to follow this usage. For example,
       parallelism means "awk and perl" and "Python and Perl" look good, while
       "awk and Perl" and "Python and perl" do not. But never write "PERL",
       because perl is not an acronym, apocryphal folklore and post-facto
       expansions notwithstanding.

> I think what a lot of people mix up is that just because something isn't as big as it was before doesn't mean it's dead.

I wonder if the Perl6 chasm tainted outsiders' perspectives on perl and the community