Niecza is an implementation of Perl6 which targets the CLR. Last I checked it lagged rakudo a bit but was still being updated and maintained.
There are other, independent implementations of Perl6. There's STD.pm which implements Perl6 in Perl6 and uses viv to transliterate portions of itself into Perl5.
Pugs is last I checked dormant, but it was an independent implementation of Perl6 in Haskell.
So if someone asks for an implementation of Perl6, they probably want rakudo. Just like if someone asks about an implentation of Ruby they probably want CRuby / MRI unless they for some reason don't. Ruby, however, doesn't really have a language spec so other Ruby implementations like JRuby chase MRI compatibility. This was a problem with Perl5 which was defined by its primary implementation. Python has the Python Language Reference for alternate implementations like IronPython and Pypy to develop against, much like the R5RS and R6RS Scheme documents. This is why Perl6 the language is defined by the spec - so multiple implementations can compatibly exist.
Rakudo (compiler) and Rakudo Star (full distribution). Both of which have been production-ready since shortly after the Perl 6.c spec release in December 2015.
Your rant would be understandable back before there was a stable spec, especially long before when the in-process language description and the various implementations were sometimes far apart. But it's been years since it had even a remote resemblance to reality.
The legacy of confusion and weirdness around the Perl 6 project is a legit problem, even/especially if it's no longer true and now Perl 6 is like a normal language.
When I ask "What's an implementation of Perl6" The answer is "Nothing implements perl 6, isn't that wonderful!" It used to take forever diving around to find something that could run some subset of perl 6, usually with the disclaimer of "This isn't really perl 6, but rather a language that seems like perl 6" And you'd get the same thing from the mailing lists/etc.