Apple II had primitive graphics and sound, but was incredibly successful.
Atari 800 featured powerful video processing with display lists and sprites, 4-channel audio, etc., but was much less successful.
As I understand it, Radio Shack did not encourage third-party software and support for its systems, not realizing that it was the key to success.
OS-9, originally a 6809 OS, seems to have survived for quite some time.