The Metal, DirectX, PS3, PS4, Nintendo and several middleware engines are C++ like.
Also the fact that OpenCL lost to CUDA for being stuck in C for so long, shows what most GPU devs actually prefer.
Aw come on, you're sure it has nothing to do with the largest GPGPU vendor pushing CUDA very heavily and intentionally gutting their OpenCL tools? Or putting out a ton of very high performance libraries with no OpenCL equivalent? Putting out a shitton of marketing and tutorial videos for CUDA only?
Yeah, that surely was totally unrelated.
Also pushing a proprietary standard goes faster than a standardized one. No surprise there.
If AMD, Intel and embedded OEMs actually produced quality OpenCL drivers, debugger and IDE support and libraries that could match CUDA productivity, maybe devs would bother to use C with OpenCL.
Even Google decided to create their Renderscript dialect instead of supporting OpenCL on Android.
I am saying that if the other GPU vendors bothered to actually provide a competing technology stack, that was worth the pain of using plain C, maybe GPU devs would have bothered.