You're thinking in x86 terms ;)
What you said. Although X86 DOS PCs could 3D render too and usually better/smoother than the Amiga on 286 or better.. (although the smoothness of 2d did not catch up till Pentium MMX!).
3D studio is well old (1-4, not MAX) and don't forget POV and Autocad. There was also lots of 3D games on DOS back then in the 80's too. MS Flight simulator, Carrier Command, Stunt car Racer, F29 retaliator, Driller...
Truespace isn't intuitive, but blender too has a long way to go in that respect.
Aww, it is! I find Blenders interface to be very intuitive. Its hard to get started but after that learning new things tends to follow a very similar logic, controls etc. I think its problem is that its not "windowsey" enough for a lot of people which puts them off.