Motorola just never learned how to sit still and continue to support and extend their platform. They got early to market with the 68000 (late 70s! way ahead of its time!) but it was a totally separate ISA and platform from the (quite awesome) 6809 8-bit chip. No continuity between them. As soon as the 68k looked a bit long in the tooth they started pushing the 88k, which was a total failure. Again with no continuity. Then they jumped to PowerPC, but they never even fully committed to that either.

If they'd done what Intel did and continued to develop on the same platform, maybe they'd still exist and we've have more diversity in platforms today. The 68000 was so much nicer to develop for than x86.

I'm not an expert, but as far as I understand, what killed 68k (and many 80s CISCs, like VAX), was the difficulty with producing an OoO implementation given the very complex instruction semantics, in particular the with indirect addressing modes.

It wouldn't be a problem today as designers have transistors to spare, but it was in the early '90s, when the high performance market was taken over by the simpler OoO RISCs and x86 [1] of which, against expectations, Intel managed to build a competitive OoO implementation in the form of the PentiumPro.

[1] which compared to other CISCs is much simpler.

They ended up solving this problem eventually with ColdFire. They dropped a few instructions and addressing modes and were able to produce something pretty performant. But just 15 years too late :-)

And now that's dead too. And yeah I think the engineers at Motorola in the 90s basically just saw the RISC writing on the wall and threw up their hands and said that was the way to go, customers be damned, meanwhile Intel just had too much invested in x86 CISC and couldn't do that and so was forced to make it work.