Or compare APIs to the car interface: steering wheel + pedals. If one car manufacturer was able to copyright them, then what are other manufacturers supposed to do? The second one can use joystick for steering, and maybe a lever for braking and acceleration. The third one has to invent something even weirder.

Everybody loses: manufacturers, because they can't easily create competing products, and users, because they have to re-learn driving every time they change car brand.