I think the thing is that the only reason to do general purpose computing on a GPU is to get extra performance. So everyone who's using the device is going to w

I think the thing is that the only reason to do general purpose computing on a GPU is to get extra performance. So everyone who's using the device is going to want to know how to optimize where a program where performance doesn't matter will default run on a CPU. And GPUs are structured to send a whole lot of memory to many processors and I think that doing this efficiently is an inherently harder problem than sending memory to a few complex processors through a pipeline that's complex, yes, but designed to make things feel easy.