That's an axiom from Alan Cooper's book "About Face - The Essentials of Interaction Design" - an excellent book for anyone who does program interfaces.
That means, don't pop up some confirmation dialog that is unnecessary or confusing or pointless. Here we are, almost 25 years into the use of GUIs in mainstream systems, and still have to deal with stupid dialogs.
Example: AVG antivirus. I press the menu option to "Update", after a moment of checking home it lists the available updates and asks me if I want to install them. There is no ability to select/unselect any, it's all or nothing. I chose to do an update, the darn program should just go ahead and DO IT!.
Example: Go to update M$ Office products. Updater first must validate that I'm using legal copies (it's checking for "my" protection!?!?) and after running the Genuine Advantage tool, tell me what a good boy I am and gives me a button I must press in order to go on. If my copy is legit, just go and DO IT! If there's a problem, that's the time to present some options.
If I bothered to keep track, I could list many more similar pointless dialogs that add no value, only frustration and time wasting. Do the designers of these things not use software themselves, experience the same annoyances? Do they not study anything about good design, like Cooper's book? It should be mandatory reading before any interface designer/coder goes to work.
Thank you for letting me vent.