I think they simply though "what can we monetize" and "how about every installation, some small insignificant fee, like 20 cents", without knowing what the fuck "installation" means. Also they purchased a company which specializes in tracking and all that shit, so they used it to track every install. "Wow, so many installations, we could make billions if we charge for each!". Also, I heard that you can avoid this fee, if you simply install other monetization into your game, but I didnt see many people talk about it, so I am not sure its a thing. 
Same greedy bullshit happens everywhere, with wizards of the cost, new owners decided that goim own nothing, and everyone owes them money, and everything is their intellectual property. It was atrocious, you owe nothing, they own everything, they can shut you down at any moment, if they dislike anything, you must visit them in person, and you cant sue them anyway, under any circumstances, you forfeit all of your rights to them.
Suddenly deciding that everyone owes them money, because they can change license at any moment becomes normal. At this point any license with "we can change it" is completely fucking meaningless. "Open game license" which wizards of the cost used for dnd was mocked years ago, and people warned that wizards can change it at any moment, but no one really listened. Most people assume that jews would not stab them in the back, they have a clause in their license against it.