Perl 6 sounds like a successor of Perl 5 but in reality it is a totally new language. Many long time Perl 5 users think a new name for a new language would have been better.
The name Perl 6 was damaging to the popularity of Perl because beginners were confused whether they should learn Perl 5 or Perl 6. The same confusion existed in Python: Python 2 vs. Python 3 but the Python Wiki was always very clear. Until a certain point, it recommended Python 2 and after Python 3 became very popular, it recommended Python 3. That sort of clarity was missing in Perl. Due to the number of new programmers learning Perl decreased rapidly and finally Python overtook in popularity.