Your statement "only a binary executable called 'perl' written by Larry Wall can parse it" assumes that perl can only be written by Larry Wall. Just because he did in fact write the original version does not mean that the perl which is the only way to parse Perl has to be written exclusively by him or even had to be originally written by him on a philosophical level. Larry having written it and it being exclusively able to parse the language fully are two disjointed facts which do not necessarily depend upon one another at all.

So, even ignoring the very good advice you've received about the behavior of dynamically parsing the language based upon earlier parsing and partial execution being the cause for the issue, your conclusion that only Larry could write perl6 to parse Perl6 is flawed.