Uh... the 68000 had, in fact, exactly 16MB of addressible space (no MMU and a 24 bit address bus).
And, I dunno, arguing about the benefits of a flat memory model on a device that shipped with an non-upgradable 512kb of memory is a little spun.
The 68k was a more forward-looking ISA for sure. In consumer computers of 1987, that didn't buy it much. Look to the '020 machines Sun and others were shipping for examples that make it more attractive.
I had a SCSI and RAM expansion for my Amiga 500. It gave me 3 megs and a whopping 30 meg hard drive!
The Amiga was so far ahead of early DOS machines, it was pathetic. Of course, by the time 486, SVGA, etc. came along it was pretty long in the tooth...
Also, I don't believe you're correct about the memory being non-upgradable. A cursory Googling suggests at least 8MB could be added, maybe more.
[1]http://textfiles.com/bitsavers/pdf/sun/Sun_Price_List_Dec88....
The Amiga had a MC68000 - essentially a 32bit instruction set with a 16-bit implementation. None of these segmented memory issues and 640K or 16M limitations existed on that superior processor of the day. The whole post is about inferior features of x86.