This is not a great comparison tbh. Unity are not distributing a resource, you could rather compare them to a company building the motor for the car you use. Even as the end customer, their product is clearly perceivable and distinguishable from competitors' products. You don't need to build cars to have an opinion on Unity motors and the ethics of their business. And if they fuck every contractor over and abuse their power in the market to retroactively charge additional fees for every time someone starts a car with their motor in it, of course you would be directly hit with the consequences as a customer. Therefore, it is justified to not leave this discussion to car manufacturers, but to 1. let unity motors know that they can go fuck themselves and 2. to support more ethical motor manufacturers in the future by buying cars built with them.