Maybe someone that's trying to use a GPU to solve a particular problem doesn't necessarily also have the time, energy, knowledge, or interest to also first 1) find out how to construct the toolchain, 2) build said toolchain, and 3) debug the toolchain. Just because you're a programmer writing code for physics simulations, image processing, AI models, or whatever, doesn't mean you also want to spend hours or days on getting your tools working before you can even start writing your own code. And then do it again when deploying on another computer.
And it's really not surprising that people, GPU programmers included, doesn't want to spend time and money on trying out unsupported hardware and software combinations when again, it's supposed to be a tool to get a job done. If I got some Phillips head screws I'm not reaching for a flat head screwdriwer even though it probably will work, and if it's the only thing I have I'll buy some Phillips head ones for the next project.