The only ones whining about that plane are the left wing military hating blogs. Billions of dollars go into research and development of things that are never used yet the libtards want to cherry pick specific things to use as an attack point.
As far as things that never flew, the Spruce goose did fly but not for it’s intended purpose. In a way it became more valuable as proof of a concept than a workable plane. In the end, planes like the C-130 would have been a lot slower in coming if the Spruce goose hadn’t proven that super transports could be built and flown.
The flying wing is another example of a waste of money on a failed plane yet it exists today in the form of a stealth bomber.
Spruce Goose also proved hydraulic systems.