I mean, look at the performance chart. CPU mode performance is a nice J curve with respect to "realistic workloads you'd actually want to GPU accelerate." I agree that having a CPU fallback is nice, but it's also pretty much the opposite of what you'd want to do in the field.
Prediction: someone deploys this and doesn't notice it's incredibly slow for mysterious reasons, and then spends several hours to figure out that the right version of CUDA wasn't installed. ("Fail fast, fail loudly" is a nice way to ensure that doesn't happen.)
Prediction: someone deploys this and doesn't notice it's incredibly slow for mysterious reasons, and then spends several hours to figure out that the right version of CUDA wasn't installed. ("Fail fast, fail loudly" is a nice way to ensure that doesn't happen.)