I don't think that's very accurate. The Atari ST had a pretty good following compared to personal computers of the time much like the Amiga... The fact is that most computer companies from back then did not survive far beyond the decade but they had their time. So it's not really accurate to say they failed when Acorn, Amiga, Amstrad...etc, all "failed", in that they didn't produce more than a handful of unique and fairly incompatible computers with no clear future, but that had a market and sold with success in their time frame none the less.