The concelt of the OR is actually a pretty nice one, not only for games, but also applications (imagine a 3D preview of a house, would be pretty, or to have a full 360 viewport for some applications), and if browsers makers supports it via useable JS APIs, that would be a nice thing to have indeed (maybe as a third party plugin though, since I hardly see how that overlaps with Scirra currents objectives), and that would still be another option, and even if an option is not used by everybody, it is still useable by the ones who needs it.
As for the VR talking, I do not care anyway, the oculus rift is a nice device by itself, but virtual reality will never be a thing I would ever want, there are I think more ways to use it than that however, which actually saves it for me I think.