I've tried running old Civ2 on a recent windows machine, no dice.
I'm sure it's possible to do that, but the backwards compatibility on Windows is definitely not as good as you say.
That said, I'm also currently, as a fun personal project, converting a game originally intended to work on 68k Macs and which still has parts explicitly labelled as for resource forks, and I've lived through (and done work on) 68k, PPC, Intel, and M-series hardware, plus all the software changes, so I agree with you about Apple.
I'm sure it's possible to do that, but the backwards compatibility on Windows is definitely not as good as you say.
That said, I'm also currently, as a fun personal project, converting a game originally intended to work on 68k Macs and which still has parts explicitly labelled as for resource forks, and I've lived through (and done work on) 68k, PPC, Intel, and M-series hardware, plus all the software changes, so I agree with you about Apple.