> It's not entirely clear why, say, an IBM AT 286 with multiple ISA slots is less suitable than an Amiga 1000 with 68000 and a single expansion slot.
The hardware might work OK but back then that AT would be running PC-DOS or MS-DOS, i.e. it would effectively not be running an operating system. The Amiga did have a functional operating system which was flexible enough to get out of the way when needed. Given that the Amiga seemed to do the job and they were comfortable using it there was no valid [1] reason to look elsewhere.
[1] bureaucratic reasons are not valid reasons, at least not to engineers. The right tool for the job, not the right tool for the acquisition department.
The hardware might work OK but back then that AT would be running PC-DOS or MS-DOS, i.e. it would effectively not be running an operating system. The Amiga did have a functional operating system which was flexible enough to get out of the way when needed. Given that the Amiga seemed to do the job and they were comfortable using it there was no valid [1] reason to look elsewhere.
[1] bureaucratic reasons are not valid reasons, at least not to engineers. The right tool for the job, not the right tool for the acquisition department.