The parent is referring to how CUDA's introduction enabled developers to write and compile C-ish code to run on a GPU, while previously programmers could take a

The parent is referring to how CUDA's introduction enabled developers to write and compile C-ish code to run on a GPU, while previously programmers could take advantage of the power of GPUs for non-render computations by hacking the pixel shaders and such, bending the graphics hardware to do something it was not designed for. You still have to write your program in a very different way in order to run efficiently on GPUs as opposed to CPUs.