i do wonder how often a technology is developed with vigor only to not sell well.

Remember 3D tvs? This is basically the same kind of ‘screen but different’ application that has limited uses and some inherent problems that may never be overcome in a way that makes them better than a simple flat screen.

There are tons of other inventions and innovations that hard work is put in to and don’t pan out. Things not working out is just part of the process!