As I pointed out on Gabriel's blog. This quote is six (6) years old at this point. Even if it was arguably relevant at the time (Alan Kay giving witness to an internal transition period in the Perl community), I'm not sure how it's relevant now.
Without specifics on which ideas Perl has that you feel don't scale, and how ... this is merely trolling by appeal to authority.
When Alan Kay made his remark, Perl had just hit its highest mark in popularity. And it just this year hit its lowest mark. So I think you've been holding your graph upside-down.
I'm sorry I completely fail to understand how either of these remarks have any bearing on scalability?
How does the Perl6 project's ability (or lack of) to deliver a project to your undefined criteria for "usable version" have any bearing on the scalability of the ideas involved in either it or Perl5?
Second, in what way does a self-described popularity contest have bearing on the scalability of a language?
I would also love to hear how you would explain http://www.tiobe.com/index.php/paperinfo/tpci/Lisp.html which Alan Kay also talked about during that interview ... far more than the single quote he made about Perl. Note that according to the scale on both the Perl graph and the Lisp graph, Perl's lowest point is roughly equal to Lisp's highest point. The obvious explanation to me is that TIOBE score has almost nothing to do with Alan Kay's comments or opinions as expressed in that interview. So I don't understand what connection you're trying to imply exists here.
Perhaps you had your book on logical inference upside down?
TIOBE is the phrenology of programming language discussions, and making changes in an established programming language is exceedingly difficult even when you intend to replace the existing version. See also Python 3000.
Without specifics on which ideas Perl has that you feel don't scale, and how ... this is merely trolling by appeal to authority.