Mainframes died for a reason, and that reason wasn't the capabilities of their specialized hardware blocks, but

a. the difficulty of using them in unintended ways, such as wiring together a bunch of them to get better performance

b. the specialized knowledge required to get them to do anything at all

c. the limited use cases of the hardware (see a.) which made it expensive

Applauding OpenCL because it is more like mainframes than CUDA... seems nonsensical to me.