If linking to external content is not viable, developers will not continue linking to external content. If developers stop linking to external content Google stops making money. It's not an infinite money glitch if Google didn't go after fraud, it hurts the profit they can make from it.
I got my AdSense account disabled because "fraudulent click activity" or how they worded it (someone clicked my ads frequently, I assume?). Google then kept all the my hard earned 16++ EUR or so.