Up until last year, I did a lot of web development in Perl. Its strengths were CPAN & community, ubiquity and top-notch text processing. Its acquired taste was very elegant expressiveness once you grokked the grammar.
Then all the Perl leadership focussed on the black hole of Perl 6 which was solving a problem no one had but CS linguists. So Perl users like me felt there was no future in Perl. Perl 6 would have to be relearned for no tangible benefit so why not learn something new with a growing rather than stagnant/declining ecosystem? No one was forced to leave, but like a trap door, as soon as a Perl programmer learned something new, they were only going to continue to decrease their use of Perl.
The rise of Python and Ruby (and Ruby on Rails especially) and even PHP, were grave wounds to the health of Perl, but Perl 6 was the self-cutting that bled the community beyond the point of self-repair.