Do you think Nikon could challenge the X system with something like this (pix)?

Yes. There are those who value a state-of-the-art device, be it a tool, a camera, a car, a fountain pen, etc. And then there are those who can live with lower grade stuff. The ratio is probably 1:99 or even much worse. Companies mostly produce what sells, not what is possibly the best technical solution. Nikon knows how to make cameras, but they also know that they need to be profitable. A company that large can't really cater to a minority.