Welp, now I officially feel old. Thanks!
In seriousness, though, this is not a very informative article. It essentially boils down to "I learned a little Perl after college, but didn't like the syntax. Then I went to grad school and found that everyone there was using Python, so I switched to that instead. Also, where's Perl 6 amirite lol."
Which is fine, as far as it goes, but it tells you more about the author's career path than it does about either language. And by doing so, it leaves out important elements of the story. Writing an article about "the fall of Perl" that only incidentally mentions PHP, for instance, is a big omission. Insofar as Perl has fallen, what it fell from is the position of leading language for building Web applications. PHP is what pushed it out of that position, not Python or Ruby. If you want to write an article about the fall of Perl you have to explain how that happened and why, but this article attempts neither.
I think the root of the problem is that the author is incorrectly generalizing from his own experiences. He mentions working in scientific computing these days; if you work in that field, and entered the workforce within the last decade, I can totally understand how it might look like The Story Of Programming Languages goes "once there was Perl, now there is Python, The End." But step outside that niche or that time window, and things look very different.