But to do Larry justice it's important to acknowledge that he specifically did not move onto a different project. He was pushed by the Perl community to start on a new version of Perl and he did so. He then dedicated a large chunk of the next two decades of his life to it, to Perl, and continues to do so, despite misunderstandings like the ones you're expressing and outright hostility from some in the Perl community. And all this while arguably he's done the best thing that could be done for Perl.
In 2000 he said:
> We have to be better, not just get there faster. ... We are determined to do the right thing by everyone. To this we pledge our lives
When asked in 2018 "Why didn't you pick something different?" he said: 
> Because I wanted to go to a Perl conference. I didn't want to go to a Perl and something else conference.
> You guys are Perl people. All of you.
> You know at the beginning we thought that [Perl 5 and Perl 6] might be a little closer together and they did diverge a little more than than we thought they would but by and large you know I think of Perl not as a particular syntax or engine but as a a set of philosophies of language design that you don't find any anywhere else in any other language. And both Perl 5 and Perl 6 follow those philosophies so on that level they are very closely related languages. They're both how I think.
> And the third leg of that is you know one can look back and say well you know maybe it would have helped the marketing of Perl 6 if it had had a different name but I'm not sure that it would have helped the marketing of Perl 5 to have a different name from Perl 6. I don't think that Perl 6 really stole any mindshare from Perl 5 at all.