Chromatic used to be a proponent of Perl6, defending it against criticism and claims of being vaporware. I don't quite remember when he became a critic, 2010-ish or so.

Around the time when Rakudo further detached itself from Parrot, and declared an effort to support alternative VMs (eventually writing one of its own).

No, I think it was well before that, and he was just more vocal at that point. IIRC became rather disillusioned with the project quite a while back, and he wasn't even involved with it (maybe nominally) at that point.

He put lots of hard work into the project, he wouldn't have done that if he had nothing positive to say. (But sure, lots of stuff have been backported to Perl 5, so the step up to Perl 6 is smaller today.)

He seemed a bit unhappy with some of the internal mess of the development, but that is not exactly uncommon for big projects.