I'm building a complex greenfield app in WPF, so your "Desktop UI is painful" comment does not resonate with me at all. They will have to drag me back to web development kicking and screaming. I absolutely love building UIs in this framework. No blockers, no bullshit. So fluid and easy.

Not to mention, the exact same paradigm translates to the other Microsoft desktop/mobile/x-platform frameworks, so if you insist that WPF is "old" or out of date, everything you build can be ported/refactored quite easily to the newest framework(s).

I have built non-trivial desktop apps in every framework except QT, and you would have to pry WPF from my cold dead hands.