I have original Kodak DC-20 and DC-50 cameras. They were incredibly expensive but absolutely brilliant for the time.
It certainly wasn't the cameras which were a failure. Kodak were more like a textile mill which had invented the knitting machine and put themselves out of business.
I am also a little sympathetic to the Philips DCC and Sony MiniDisc. Apart from the nonsense to prevent CDs being boot-legged both were just too late to market, arrived just as alternative and better technologies were emerging.
Not sure I would be so generous though when it comes to the Sinclair Microdrive.