up-side

It means that, if applications implement the standard correctly, an individual can't ACCIDENTALLY copy information from the document or print the document. That gives the company deniability and shifts the liability for violations to the individual who broke the rules.

This is important to many companies. My previous employer often set the no-copy/no-print flags on PDFs that were covered either by internal distribution restrictions (e.g., registered company secrets) or external restrictions (documents received from third parties with restrictions).

The point isn't to make it impossible to copy (they would love to do that, but recognize that it's impossible in an era when every mobile has a camera can take screenshots), but to make it obvious to people when they are breaking the rules.