Most Linux distributions contain ungodly amounts of Perl.

The only person I've worked with over the past 20+ years who used Perl was a bioinformatics guru. When he taught students in the lab, however, he'd switch to Python.

Bioinformaticisn here. While Perl has been popular in the field, R, Python, C/C++, and recently Rust are more common these days. I think it mostly has to do with the fact that bioinformatics used to be mainly dealing with huge text files (FASTA, FASTQ, SAM, BED, GTF/GFF, etc.), and for that purpose Perl is not a bad choice.

As the cost of sequencing keeps coming down, we sequence deeper, and the computational demand goes up. Plain-text is replaced with binary formats, and most of the heavy lifting is now done by compiled libraries. The benefits of Perl aren't really relevant anymore, and given the choice most of us simply prefer writing Python or R.