The root problem here is the concept of patents -- at least as far as I can see. If patents did not exist, and nVidia were to close down ARM and tell people "n

The root problem here is the concept of patents -- at least as far as I can see. If patents did not exist, and nVidia were to close down ARM and tell people "no more ARM GPUs; only nVidia GPUs from now on", then a competitor who offers ARM-compatible ISAs would quickly appear. But in the real world, nVidia just bought the monopoly rights to sue such a competitor out of existence. It's really no wonder nVidia did this given the profits they can extract from this monopoly (on the ARM ISA).