I just spot checked a Fedora 8 box, and in /usr/bin and /usr/sbin, there are 2706 executables. 580 of those are scripts. 142 are perl scripts. So it's really more along the lines of about 5% of "programs" being perl scripts, and less than 25% of scripts being perl scripts. Also, I would imagine that the perl scripts would mostly fall under the category of command line utilities as opposed to full-blown programs, and would thus be easier to port to, say, Python.
What in the world made you think that 'A huge majority of "programs" on most Linux distros are actually scripts, and Perl scripts at that', BTW?