I occasionaly see the response that devs should have been prepared for something like this, both because the TOS laid some groundwork for this, and because it is in line with the way the current owners of Unity want to operate. The fact that they deliberately tried to obscure that something like this might happen is no excuse by this logic: as a gamedev you should always be hyperaware of the terms you are working under and read everything you agree to as carefully as a lawyer.

My response to that would be: even keeping morality out of it, Unity's bussiness is specifically making the job of gamedevs easier. Forcing people to keep up with every detail of the terms on which you are using their engine undercuts the value of their product in exactly the same way as e.g. making their engine twice as slow, or making it much harder to port to different platforms. It forces their users to take their attention away from the actual job of making the game.

In that view this isn't just a pricing change, but a fundamental worsening of their offering, which is meant to be a streamlining of game development.