only Japan has a management culture weird enough to keep pumping money into half-baked products like MiniDisc without anyone batting an eyelid
That's not true. The MiniDisc was a great product, I owned and used one for a long time. In Japan it got a pretty decent success, a MD player was usually embedded in hifi systems, and it was also used to exchange data. One problem if any was the DRM (for MDs having music like CDs).
The main problem that was not mentioned here yet, was the Western protectionism. Western countries wanted to slow down the electronics invasion coming from Japan. MD was not "revolutionary" enough to create a need in Western countries that would have counter balanced the anti-Japan products protectionism.