I ran into similar feelings from my manager while working for UtiliCorp United, Inc (was Enron's main competitor). In a nutshell, perl has many advantages over shell, even a supported shell.
1. Massive User Base - if the job isn't getting done with current staff, there are (literally) thousands upon thousands of programmers who CHOOSE perl on a daily basis and can come up to speed on any perl project in no time. (This makes recruitment far easier - there are more potential perl coding staff already available than most any rapid development language)
2. High Presence on servers - stock setups of most any Unix-like OS come with perl preinstalled, even companies like Sun who wish to squelch open sourcers choose perl as a vital component of their systems.
3. Rapid development with a wide variety of API's - Perl's easy integration, rapid development times, and support for a VERY wide variety of other software and hardware make it second to none. A Perl module can be quickly found or built to create a simple, useful API for most any need.
These are just a few examples summarized from comments
already posted. Perl is fast, compatible, easy to use,
widely supported, and very reliable - all the core needs of an enterprise rapid development environment.
"In my line of work, I don't invent many wheels. I just custom fit wheels already in place."