This only makes sense. Unity is a very big part of what makes a game work and building and maintaining the Unity engine costs a lot of work. They deserve some share of the money made on a game. That share should ideally be proportional to how much money is made by the developer, which should be proportional to the amount of times the game is downloaded. And this is only one of their plans. There are other plans as well. So maybe someone can explain to me why this is not just a sound business decision apart from: I don’t want to pay any money?