If they do any amount of command line wrangling, you should hope that your employees are writing code like this every day. The whole point of these one-liners is that once you get the hang of it they're very powerful additions to your *nix pipeline.
They could write highly maintainable, well tested, peer reviewed etc code to do the same things, but in this context that would be hugely wasteful, as the utilities already exist.
This is Perl as a replacement for Awk, not for Java.
Being able to create that line-noise is, in most cases, significantly more useful than taking 3 months to create a perfectly engineered recursive phone-number finding program.
They could write highly maintainable, well tested, peer reviewed etc code to do the same things, but in this context that would be hugely wasteful, as the utilities already exist.
This is Perl as a replacement for Awk, not for Java.