That might be a good thing for you and your customers in the short term.
I'm not sure that's going to be a good thing for everyone in the long term, (but it doesn't bother me as long as I don't think about it).
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.