AMD and Intel don't actually own it all, certainly not from a software perspective. That's the difference here. The upshot of this article is that Nvidia basically wants to "CUDAify" the entire datacenter software stack. Intel and AMD absolutely do not have that kind of lock-in. You don't need to use their proprietary language to write programs that run on their systems.
Plus CUDA shows what can happen even when alternatives are available (OpenCL for example) you just have to use the hardware / software integration to be sufficiently ahead and establish a virtuous circle.
