Because they have a near monopoly with Cuda and get away with dragging their heels due to lack of market pressure (everyone loves to lock themselves into Cuda and then complain about GPU prices), despite having been on the OpenCL committee (just like Apple with Metal conflict of interest).
Anyway, I'm very glad to see it and will be using it immediately.
Also because none of the competition were/are serious about OpenCL either.
AMD still doesn't have OpenCL 3.0 support and their implementation of previous versions was far far less stable than CUDA.
I can't find a definite source on this, but afaik none of the official OpenCL implementations have ever fully supported mixed CPU-GPU code the way CUDA does.
AMD's OpenCL support on GPU is overall excellent in my experience (2x commercial apps and lots of hobby code), but I tend to mostly use low level OpenCL 1.1 stuff, which I find sufficient.
Also Intel GPUs are actually incredibly competent with OpenCL if you give them wide enough NDrange, and somehow try to look past lack of any fp64 support at all :/
On top of that even the "do no evil" Google, never supported OpenCL on Android, pushing instead their own dialect, Renderscript.
Yes, there are some custom Android deployments that have a libopencl.so kind of thing, it is used by the OEMs themselves, and never exposed as official Android API.
