Unfortunately, that's almost the purpose of patents in general. In many industries patents aren't usually licensed so its even worse. In those you don't extort for money, you have an X year monopoly on a whole technology.
IV is probably the best example of don't hate the player, hate the game. They've looked at the game and figured out how to play it. It's like the expert Scrabble players who know all the Scrabble words, but none of the actual definitions. It's completely legal, but probably not in the original spirit of the game.