Fair enough, this is an atrocious billing system, but I I firmly believe that this is simply a gimmick to get around charging royalties without calling it so. Maybe I am biased, but the people working at Unity are not monsters, and I believe the employee who posted publicly and stated that the people implementing this system made sure that it would be under-reporting installs is speaking the truth. I think there is this misconception that Unity is simply gonna fire an event for every install and charge you directly for each report, but there is no way that this will be this simple. In all likelihood they will use this to keep a list of the popular games, and the actual fee will be based on heuristics like estimated sales and whatever other analytics and ads generated by the game clients. Sure it is a "trust me bro" system, yes it's bad, yes it could be abused, I think it is fair to call it out and ask for a more transparent system, but deep down I just don't believe that Unity is evil and did this to abuse the developers.

In all likelihood THEY will be the one forced to under charge, and really they're doing this to force you into their ecosystem so it is likely that they will reach out the studios individually before incurring the fees. The whole thing is worded in a way that past a certain level of success, they will charge you royalties unless you play ball with them and serve ads and buy in other services. I would not blame anyone for calling it scummy, but I think it is important to understand their motives, they want to force your hand to use whatever they're selling. The installation fee is just a smoke screen, they have nothing to gain bankrupting studios by making up numbers. Of course, this is just my own take. I think I have a fairly good understanding of how they operate, but I could be wrong.