Easy to say to mobile games studios that have ben using Unity for the last 10 years (or where in the process of releasing a game after multiple years of development) and didn't have to pay that tax before.

Also this will apply to every games made on Unity, so if you have a hugely popular game just above the threshold but make less than 0.20$ per user you effectively need to shutdown it down.

It isn't "bad business model" either, there is definitely a market for games where the revenue per user is less than 0.20$ (or whatever number).

Going with % of revenue is the sensible decision, just like Unreal does...