Geez, I guess most people don't get as tweaked out by unplayable keyboard/mouse controls, non-remappable controls, controls that are remappable, but still use the default scheme in certain situations, and all the other console badness that leaks over into slapdash PC ports as I am.
UWP has literally nothing to do with any of those things. UWP means we can release on both platforms without re-writing our whole rendering pipeline, memory management and network code from scratch. One code works everywhere. If companies are sloppy and don't provide good controller options then it's definitely not because of UWP.
