gfortran also does not do GPGPU.
It was quite surprising to find out the lack of understanding from Khronos that CUDA supports Fortran out of the box, during OpenCL 3.0 Q&A session.
I can code with CUDA in many more languages than fortran. If I wanted to use gfortran, I just would make a wrapper to CUDA with C++.
Yet, inline assembly is not part of ISO C.
Or one that generates lousy machine without full advantage of the CPU vector units.
Yet, vector instructions are not part of ISO C.