should I really let him go deeper into outdated technology

Perl does not fall under the "outdated technology" banner in my opinion. Sure, it might not be the latest sexy, shiny language but that does not make it outdated.

Having written code in a number of languages with varying degrees of success, I feel Perl is the easiest and most versatile among them. Hence it is very much my language of choice.

There is a rather intetesting article that addresses this issue of Perl being outdated. It points out just how different Perl is now to when Perl 5 first appeared despite the name implying they are similar.

I wish I had discovered Perl in my early days of programming. I learnt BASIC from a textbook and wrote lots of code by hand with a pen and paper before I ever got the opportunity to test that code on an actual computer! I was about 12 at the time...