Here's a few relevant quotes about the author's intentions:

"I am not trying to introduce most principles of good software engineering."

"Well, if I am not trying to do all of that, then what am I trying to do?"

"I am trying to do this: create a book that will help my twelve year old twin brothers learn to tinker."

"This book is not an attempt to immediately achieve the end result of a good programmer in all regards. It has a goal which might be called more modest, but which I believe is ultimately more important: that of lighting the child's fire. Once the fire is lit, it can be tended and carefully pruned; there will be plenty of time for the channeling and discipline necessary to let the fire achieve truly great things. I am not trying to do everything; I am trying, for now, to do one thing well."

CJS Hayward, 7-16-98

"P.S. There are some intentional inaccuracies. This is because a fully technical treatment of the issues involved would, I believe, needlessly confuse children. Some parts are oversimplified; I intend them to be overridden by more nuanced treatments when an appropriate level of intellectual maturity is reached."

That's how I learned Perl, by tinkering through telnet and hacking free scripts by trial and error, not even knowing about perldoc! The fire was lit. Our knowledge evolves!