Navagon: Such is the fate of closed systems. I don't know what happened to Atari and Commodore, to be honest. But I bet it boiled down to Apple having the soundest business plan. They had already targeted themselves at a market which is more sustainable for repeatedly buying whole new systems every few years.
Whereas Atari and Amiga were more in direct competition with the PC; and as closed systems they perhaps proved to be less desirable in the long run.
dyscode: It wasn´t the closed system that brought the Amiga down, it was maybe the 1st and ultimate victim of piracy. So no one wanted to develop for it anymore.
Agreed some late decision at Commodore did not help either but piracy finished it off.
Also essentially Amiga was UNIX/BSD based. So that´s not the point.
Apple was a similar a closed product by the time also. But the market was less gamer and more professionals & businesses. Who could actually afford it.
Are you really sure that a closed system was not a factor against them?. The gaming industry is a hightly competitive sector that requires hight tecnical improvements. On a open plattform like PC Cyrix and Intel developed awesome processors, Creative awesome sound cards, S3 great graphic cards... A company can´t be a leading one in every aspect. So the old gaming computers were replaced by modern consoles, a simple system oriented only for gaming.
Maybe I´m mistaken but I think Amiga OS is not a Unix based one. Later, at 1990 (not sure), they introduced a Unix based one called Amix, but software developed under Amiga OS were not compatible. Don´t blame me if I´m mistaken, I was only ten years old, so can´t be totally sure.