Yes, but as you said, you can’t know if you’ll like the game or not until you try it. It works with standalone games as well if you pirate before buying, but it’s usually not aimed at pirates: no one sane will pirate a game, find out they dislike it, and buy it anyway. It goes without saying.
It’s more the people who already bought games that need to hear that “so you bought the last two mainline Pokémon games and they both sucked ass? Don’t fall for it again, vote with your wallet and stay away from the next one”.