The fallacy in your thinking is that you’re looking at it in terms of a closed loop.
There are successful hacks of Apple’s OS onto Intel PCs. I don’t think that’s a mistake, and it’s probably keeping worried lights on at night in Redmond.
What Apple can do is keep the lid on the OS and the hardware, and maybe someday let the genie out of the bottle, either by licensing clones or letting it loose in the wild.
I think the former is more likely, with a tightly controlled product line.
In the meantime, there’s no reason for them to abandon the current business model: it’s only a small part of the market as a whole, yet they’re making money hand over fist.
Deservedly so.
It sounds like the Mac is the best platform for the specific kind of work that you do, but distributing that work to your customers is problematic if they're running Windows. I can sympathize, and I can appreciate that putting MS out of business so they'll buy Mac's would make your life easier.