The article paints UWP as a modern programming environment, superior to Win32, that only 'lazy developers' would reject, when in reality it is a confusing mess of desktop and outdated mobile paradigms from 10 years ago when mobile devices had dramatically less RAM and were much less powerful then 'real computers'. UWP is in many ways worse than Win32, it requires much more boilerplate code to get stuff done, and requ…
The main thing limiting C++ code in UWP is sandbox, not the compiler. C++/CX is a glue language between proper C++ and the rest of the OS - you can freely mix it with proper C++ (11, 14, etc) within the same binary. I successfully compiled many open source cross-platform libraries for UWP without any serious issues.
As for complexity and generally APIs, UWP is way better than old Windows APIs. It is fairly consistent, predictable, and modern. I'm guessing you are really used to the old ways, but I don't really understand how can one prefer WndProc / manual message handling or message maps to clean approach of XAML; or think it was better.