> Perl was the language best suited for text manipulation because of its early popularization of regular expressions.

It was awk, grep, sed, and lex that popularized regexpes before. Perl attempted to agressively replace awk and sh, even shipped or still ships the a2p.pl script to perform limited awk-to-Perl code conversion. What Perl brought were Perl-style regexpes with capture groups and back references, which are still not characterized in terms of formal language theory when good decision procedures were the entire point of subsetting lexical analyses from eg context-free languages or other more capable models, which is particularly odd considering Larry Wall is a linguist.