For many people, being creating notes on paper copies is the way they best learn. Again, this indicates the information is available in an offline format. It is simple for many people to wonder why people wish to print websites, however, our responsibility is usually to create content accessible _ within the best format for all our visitors.

If best format is printed to paper, then who am i to argue?

WHY WOULD THIS PAGE BE PRINTED?
A very good question ought to when searching out the content to feature or hide in the print stylesheet is, "Why's the person printing this page?" Well, maybe we have a recipe they'd like to go by while cooking in the kitchen space or take with them while you shop to order ingredients.
Or they'd want to use a confirmation page after buying a ticket as evidence of booking. Or perhaps they'd like a receipt or invoice to get printed (or printed to PDF) in an effort to store it from the accounts either as paper or electronically.