> There are many languages still in use today that have all kinds of warts and ugliness, but they remain in use because they still have momentum and lots of legacy things built in them. So being ugly or old isn’t enough of a factor for people to abandon something in droves.
Nothing forced anyone to abandon Perl 5 code, and I suspect most Perl 5 wasn't abandoned for its own sake; it was a Cambrian explosion of new greenfield projects rising out of the ashes of Web 1.0 that brought Python and Ruby and PHP to the forefront. It's just that a lot of the Perl 5 code out there in the world was quick and dirty CGI scripts that died naturally after the dotcom crash and as the web became more sophisticated.
(There's stuff about the perl language, but that's probably secondary.)
PHP arrived and ate into it's web app use-cases. Modperl wasn't great for hosted environments, to say the least.
Python matured and started eating into it's systems use-cases and eventually the web use-cases as well. And was just so much easier to work with and learn.
Perl was left with no real niche where it really shined, except one-liners and making poetry I guess
Perl, Lisp, Haskell, Prolog etc.
I was there when Perl ruled the world, I used it myself to rule the world. The scene was always managers going to the C++/Java teams and asking them an estimate to a get a project done. They would often come back with timeline spanning 1 - 3 years.
Perl teams would get it done in like a week.
Needless to say most non-Perl programmers wanted Perl gone for this one reason alone. Too powerful, people who know how to use it make too much progress compared to everyone else. Smaller teams making larger progress shrinking the head counts, which top bosses didn't like.
Programming world is a sea of mediocrity, good things mostly don't make it here.