I think it's a combination of multiple factors. I worked with GPU kernel codes before and the code that you write has a tendency of never being updated or modified. once it works it works perfectly and you do not change it. if you get new hardware you're going to fully rewrite it. so, typically readability is just not useful. also, you're never working with variables that make sense to humans. it's never something tangible. it's always tiles, offsets, indices. i do not think, at least when I was writing the code for GPUS to waste space visual space on better variable naming was worthwhile.