I disagree with the first sentence. In 199x the first people I knew making web pages dropped perl scripts, not C programs, into cgi-bin.
May have pre-dated you by a bit. Perl definitely took foot not long after but the earliest cgi-bin days were dominated by C before people got tired of fighting compilation for web apps.
IIRC the spec itself says it was built for C applications.
mod-perl was a godsend, of course.
Perl's CGI.pm was updated as recently as 5 months ago :)
https://metacpan.org/pod/CGI