A better analogy is this, You buy a paper book but it comes inside a big glass box so you can't xerox or scan it. To read it you have to use a key that you received that will unlock a stick inside the box that you can control to turn the page. A pirate buys the book, brakes the glass, makes many copies, all the pirates then can read comfortably, can take notes on the book, can go fast trough the pages, yopu the person that uses the legitimate DRMed book you use it in a uncofortable way, you can't make notes, skipping trough pagers is super hard, lending it to a friend is impossible. So DRM made it harder for legitimate users, for pirates is still easy.