I don’t think it’s just questionable, but an attack on human art based on an out-of-control capitalism. And I hope this is just a bad-tasting joke from Unity. In Godot I don’t see a solution, it’s a program still with so many problems in physics, collisions and 3D dynamics that is supported by the community that changes the source code while the official developers are obsessed with releasing new versions on new versions. And I’m afraid that soon or later they’ll give in to the desire to make millions upon millions on the shoulders of creators.
Maybe they can force you to have an account linked to unity and start a pop-up for every launch of a unity-marked game.