If UWP is supposed to be a successor to Win32, then shouldn't it set a base minimum goal of being as easy to use, as resilient and plain and simple "just work"?
It's not up to consumers to accept bad software, because Microsoft has to reinvent the wheel. Look at a good (well, better at least) OS: Most Linux operating systems have switched to a more secure sandboxing environment, without having to rewrite everything in a new API. Sure, it does take some work, but it's additive. And from I gather, with Wayland support growing, close to "done" at this point.
At the same time, Windows 10 keeps breaking basic things for this all the time, and even with a tool that helps to transform Win32 into UWP, I don't see any big push from 3 parties (think browsers, production tools, and so forth) offering UWP versions. Having a well functioning store, with a central working update mechanism would help bring Windows to the 21 century. But alas.