Bad compilers would be my guess. And not only would it make sense for Intel to push OpenCL for Deep Learning, but it would make sense (IMO of course) for them

Bad compilers would be my guess. And not only would it make sense for Intel to push OpenCL for Deep Learning, but it would make sense (IMO of course) for them to push OpenCL as a much better abstraction for accessing the vector units in all their CPUs in a multicore fashion across the board.