If you read the book, you may agree on a certain practice, and therefore use perlcritic to check that your code is adhering to it.

If you disagree (but you should at least read it before saying so) you can always disable the checking of that rule in perlcritic.

The rationale of the book, and of percritic as well, is to ensure that a group of programmers use a consistent set of rules. And "a group of programmers" could be you and the one maintaining your code 6 months from now, and that could be you again.

I personally disagree with some of Conway's recommendations, but I like the principle.