Of course part of that is technical, but part of 'marketing' is understanding what your users want and delivering it to them.
This article I wrote about Tcl a while back is what I'm talking about: https://journal.dedasys.com/2010/03/30/where-tcl-and-tk-went...
Yeah, but you keep pointing to things that are exactly like many successful projects as wrong, like having a different name for the language vs. an implementation vs. backends used by the implementation.
I will suggest that the two things they actuallt got wrong were:
(1) Calling it “perl”, and
(2) Taking forever.
And, really, those two in combination: even being as distinct as it is, had it stabilized in a reasonable period of time, and had once it stabilized a reasonable transition path been provided, it might have been another Python 2 to Python 3 problem, but not a complete disaster. Conversely, ha for been a new experimental language and not “Perl 6”, taking forever to stabilize would have been more tolerable.