This is not a shame, this is the logical consequence of all to lies told to the Windows Phone community, which could have bootstrapped UWP but was totally demotivated when UWP was released.
But the main reason is the stupid decision to make UWP available only on Windows 10, at a time where Win7 had the highest marketshare. Microsoft should focus on making WPF multi-platform if it wants developer to be excited again to develop native software on Windows.