I suspect the advice is meant for more or less 'normal' Windows Admins, and I don't see a lot of them even knowing that Perl exists, let alone installing it on Windows machines ;)
Just goes to show that having broad knowledge of tools and languages can be a lot more helpful than knowing just one language in depth.
(Was it me, I'd probably have done it with Excel as well, automating with VBA to include the actual diffing..)

C.
(Hmm, is 'diffing' a word? ;)