By "can't use it" i just mean 3DNes starts as a non-VR emulator for a very long time before fully support VR so most users purchased it to play on their PC without VR headset so they even just don't have a headset to play Steam 3DNesVR version. That's what i mean.
"Are you not allowed to provide the non-VR functionality?" : I'm allowed and i can do it. But putting everything, every feature in the same code takes a lot of time trust me. I'm eventually planing to do it but i don't think i could finish it before Steam release.