It's not as simple as calling it theft, but it is simply theft, plus the other good points you made.
I think once it becomes infrastructure and widely used knowledge the authors can't claim control anymore. Or shouldn't.
This is a big eye-roll but otherwise ya, this is one way to think of it. It's not all about money, though. The people running these companies are just taking, en masse, without credit. This is a basic human desire. Of course there is a discussion of whether or not we should evolve beyond that. It feels incredibly dystopian to me, though.