I had to be done in ten days or something worse than JS would have happened.
For a programming language designed in 10 days, he did an amazing job. Maybe he did too good a job: his first draft was good enough to use, and so he never got a chance to fix the language’s flaws.
Perl 6 has gotten a lot of ridicule for being so slow to come out, but it may have the last laugh. Someone learning Perl 6 in the future will not care how long the language was in development, but they will appreciate that the language was very thoughtfully designed.
Perl 6 really is a new language, compatible in spirit with earlier versions of Perl though not always in syntax. Damian Conway has suggested that perhaps Perl 6 should have been developed under a completely different name. Then after it was completed, the developers could announce, “Oh, and by the way, this language is the upgrade path for Perl.”
If you think of Perl 6 as a new language, your expectations are quite different than if you think of it as an upgrade. If it’s a new language, it doesn’t matter so much how long it was in development. Perl programmers would be pleased with how similar the new language is to their familiar one, rather than upset about the differences. And people would evaluate the new language on its merits rather than being prejudiced by previous experience with Perl.