[nl]

If you compare the effort that AMD spends on OpenCL compared to what NVidia spends on CUDA then you'll see why everyone just used NVidia.

I'm not a big fan of vendor "standards", but I have very limited sympathy for OpenCL here.

I think the best hope for portability is at the higher level programming API layer. For example TensorFlow is careful to make switching between CPU and GPU painless.

[oneofthose]

It would not have to be like that if Nvidia opened up the source-code for cuFFT/cuDNN/cuBLAS. My guess is they are not doing that because it is fairly trivial to port code from CUDA to OpenCL. It can even be automated.