I agree on the basic premise: simple, or simplistic, Perl should not be frowned on; unless it's for a bank or a million hit per day site or something. But simple does not equal wrong or sloppy. I wrote a lot of crappy, naïve code myself that got mountains of work done without, for the most part, incident while boosting the reputation of Perl in the non-techies around me who were unable to detect the odor of code but were able to see how fast Perl could do things. So I know exactly how valuable even bad Perl can be.
It's possible to teach simplistically without teaching incorrect things. It's also much harder to relearn something you were originally taught wrong than to take the time and effort to learn something right the first try. Once something goes through a publisher and has an ISBN attached, it's open for stronger critique than if it were just some dusty corner of the Internet.