The counterexamples you provide (OSX and Chromebooks) follow basically the same UI paradigms as the Windows machines they replaced (even if some of those might have been copied from earlier Macs). There still may be less overall diversity in the computers we use, even if there are now a number if different logos on the box.
Edit: I do see that HP made graphing calculators with native RPN in the late '80s, so perhaps they were pushing these for academic markets, although today they seem to be the provence of surveyors.
Random aside: I first learned RPN from my father, a budget analyst, and have used it ever since. RealCalc is an Android calculator app with an excellent RPN mode, if you're curious.
Before Python, I ordinarily used bc (a Unix command that acted as a basic calculator) for simple calculator calculations at my desk. bc was much more popular that the other Unix calculator dc which used RPN. Now I just use python's REPL. I only use a calculator if I'm away from a real computer (which is rare since I carry a smart phone).
It's more cumbersome for a single arithmetic operation, but when you're chaining operations together the stack is very powerful.
It's a lot less abstracted from the way the computer works.
I think games used to be the big differentiator for many people, more so than office software, but now the gap is decreasing rapidly on all fronts. Apple needs to revisit the Mac mini as a low-cost entry into their ecosystem and make it an attractive PC in its own right as well. I know they're going to be adamant about GPU upgradability, but they should at least promote the Thunderbolt-based external GPUs and help them be a viable solution.
It's not necessarily bad, it's just a different philosophy; some prefer computers to be appliances, like their TV or refrigerator, that "just work." Others prefer computers to be DIY-servicable machines, like cars, that require active and regular maintenance but can be improved if one is so inclined.
Just because all the "appliance computer" manufacturers almost went out of business going into the 1990s, doesn't mean that philosophy failed, and the recent resurgence of Macs has proven as much.
I suspect in an alternate universe/timeline with slightly different twists of fate, the IBM PC has died instead and closed proprietary hardware is the dominant paradigm.
It is necessarily bad if you make yourself (or, more important) your business totally dependent on somebody who is a monopoly supplier.
> doesn't mean that philosophy failed, and the recent resurgence of Macs has proven as much.
I think all the proprietary systems failed, and there were dozens if not hundreds of them. Apple was the only significant survivor, mainly for pseudo-religious reasons.
The only areas where proprietary systems survived are in mainframes (perpetuation of IBM monopoly) and in games consoles (where hardware can be sold at a loss).
If the IBM PC had died, the world of CP/M would have continued....
> the recent resurgence of Macs has proven as much
Not really. The recent resurgence is mainly due to the fact that its lack of serious and/or business software is not the barrier it was when (a) most people can do most things online and (b) it has Unix underneath.
I don't think this is as big of an issue as you think. I would be part of that generation. Almost everyone I know (and I mean regular people, I don't have many tech nerd friends) has switched to OS X in work and personal life. A few are on Chromebooks too. Most use a mixture of MS Office (when required for work/college) and Google Docs. So although I agree that there was an MS monoculture when growing up through the 90's/00's I disagree that has led to lifelong loyal custom.