Well, unity's business model was always to make it free and then ask for a fee on revenue because it's easier for small studios. The alternative business model would be to sell a direct license of the 3D engine, which will likely cost in the 10s of thousands.
It's expensive building a 3D/game engine, they sell one to you.
I'm not saying their latest move is not a real dick move, but it's normal that they want to be paid for the product they sell. Uber drivers have paid for their cars, right?
Again, I agree that Unity's move is bad, they're just forcing people to their monetisation platform and to a per download system which will hurt a lot of studios.
The 3D/game engine for a studio is, in my opinion, the main tool that game studios will r to make their game. Without it, they won't be able to develop or it would cost them 100 times more. That's why I compared to the Uber driver's car, it's also his main tool for his job. Both cannot expect to have it free.