Comment by indymike

The 268 had a segmented memory model which effectively made it possible to only access RAM in 64K pages. The 68000 had a flat memory mode and other differences that would have made a port of AmigaOS to a 286 very difficult because of the downgrade in capabilities (video controller architecture is another huge issue, too). In many ways the 286 should have been awesome, but wasn't. The 386 was more of a 68000 series competitor, and I believe it came out about the same time as the 68030 - so by the time Intel chips could compete with Motorola, four years had passed (and in that era, four years was like two decades).