I can understand what you mean, but let's be fair -- preventing things like "all white UI" can easily be coded into the configurability. Yes, the full iteration of possible situations you could get into are quite large, and maybe you miss some -- but there are also options for coding in some kind of "reset" quick-switch that doesn't require the UI.
Also, I'm not sure I buy the claim that "things like that are tolerated a lot less". Are they? Or has it just been so long since we've had anything like that, that we just assume people would hate it even more?
Well, I'm sure you'd hate it if your smartphone would keep white text labels without outlines on your home screen if you set a very bright custom background. I've just tried it on my phone: if I set a mostly white background image, I can still use the home screen because the text also has a dark drop shadow (for exactly these kinds of situations!). That illustrates my point quite nicely I think: there are fewer settings now, but - when done right - those that are available behave quite well.
Theming was just the first example that came to my mind. It's a pretty benign one in the grand scheme of things. There were other ways in which you could misconfigure your system. These were also the days before PCI, USB and hardware auto-detection. You could easily pick the wrong driver and/or wrong settings for some hardware and the system would mostly just try to run with it, not knowing that anything was amiss. Pick the wrong mouse driver? Set the wrong COM port for the serial mouse? Tough luck.
Also, I'm not sure I buy the claim that "things like that are tolerated a lot less". Are they? Or has it just been so long since we've had anything like that, that we just assume people would hate it even more?