Digging through Usenet archives, I found a post from John Mashey discussing the RISC-CISC spectrum. I found a copy here:
https://userpages.umbc.edu/~vijay/mashey.on.risc.html
The M68K gets called out as having some really complicated instructions in it,
> We thought that adding more addressing modes was the way you made a machine more powerful
https://www.computerhistory.org/collections/catalog/10265816...
People get caught up in intuitive notions of “complex” or “reduced” when talking about RISC and CISC, so it’s very helpful to have specific ideas about what of problems you’re creating for yourself years down the line, when you’re designing an architecture in the 1970s or 1980s. The M68K has instructions that can do these complicated copies from memory to memory, through layers of indirection, and that creates a lot of implementation complexity even though the instruction encoding itself is orthogonal. Meanwhile, the x86 instructions are less orthogonal, but the instructions that operate on memory only operate on one memory location, and the other operands must be in registers. That turned out to be the better tradeoff, long-term, IMO.