Its simple, there were a lot of other options that were less expensive.
At the time, except for gaming, the additional features of the Amiga chipset were of limited utility.
I don't agree with that myself at the time Macintosh was extremely expensive and PC wasn't that much better. (PC cloning ultimately lowered the cost.) Both of the other platforms which had abysmal graphics and limited sound at the time and were crippled with at best cooperative multitasking or no multitasking at all.
The Amiga quite simple offered a platform that was equivalent to most of what a modern PC offers with far less horse power required. At a very competitive cost. The fact that Commodore failed to sell millions of units in the US was simply do to marketing them in the wrong locations with the wrong message.
I believe that the reason Amiga failed was a complete lack of vision by Commodore Management that really didn't know how to compete in the developing computer industry market. The needed to allow cloning and market two series of computers and a gaming system. A productivity business series, a home users educational system, and a gaming entertainment system. Commodore sort of had this with the model break but they did a horrible job of marketing it.
-Nyle
