Edit: sorry for the confusion. I meant popularity-wise. I wish the change would clarify to people that Perl 6 and Perl 5 are basically two different languages and people should at least consider Perl 6 as an option when they start a new project.
The features demonstrated in this talk are worth a watch (or at least a scroll through the slide deck): http://tpm2016.zoffix.com/
Over the years (announced in 2000, delivered in 2015) it evolved into a distinct language.
In the meantime, Perl5 suffered from the Osbourne Effect.
Meanwhile a rift developed in the Perl community. Some are for Perl 5 forever. Some are Perl 6 forever. Some Perl 5 people blame Perl 6 for Perl 5's perception as a dead language. Some Perl 6 people blame Perl 5's reputation for being "write only" and "dead" for difficulty getting people to try Perl 6.
IMHO, both sides are correct, both sides over-state their case.
Renaming Perl 6 has been discussed for close to a decade, by people who are Perl 5, Perl 6, and just plain Perl partisans.
It's been a difficult decision. Many people have worked very hard on both projects, and have strong feelings tied up in the issue. Important contributors to the projects have quit as a result the issues.
This isn't a change that was lightly made. It's far bigger than the Python 2 to Python 3 divergence. It's more like moving from C to C#.