I think that opinion going to vary according to the person…
I argued back in 2007 when Mac development started that this would be a nightmare for teachers and anyone else who is working in a mixed environment - which currently is way more than the ‘few isolated cases’ originally argued - plus it also means doubling a large number of training resources, tutorials etc. Anyway I didn’t win on that one, so here we are.
That being said, I have had to teach mixed classes - there are a couple of ways to go, but some of them depend on resources you have. I was lucky to have a university lecture hall equipped with a dual-input beamer system, so I brought my PC and my Mac and did alternate exercises on each one.
The alternative is actually to force Mac people to use the Windows version via Bootcamp or even Parallels/VM) and teach the class on Windows Rhino - the Mac people will learn Rhino at least, then they will just have to get used to the Mac interface later. I do this currently with my modelmaker apprentice classes, but most of them have Windows at work anyway, even if they have Mac at home.
Going the other way (teaching with a Mac OS running on Windows) is as you well know not possible - well maybe it is possible via a VM, I have no idea.
I think trying to create a more Mac-like interface in Windows Rhino will not help much, you can do some small mods to make it look a bit more mac-friendly, but cannot fundamentally change how the Windows Rhino interface works - any more than you can change the way Mac Rhino works.
There is maybe one last way to have everyone’s interface look more or less the same… Teach full-screen only and have everyone type all commands.