The reason its a big deal is because it tracks owed money by installs. This includes pirated versions btw. Meaning the devs using Unity would get a bill from Unity for every copy of the game, legal or illegal, that had ever been installed anywhere. One person could script a bot that installs a game on a junker system 1000 times an hour, and bankrupt the dev who'd have no legal recourse. If this sounds retarded as hell and like something Satan would invent, you now understand why everyone is so mad.