Honestly, if I had to develop a new desktop app for Windows I would seriously think about Electron. It's frustrating that there is no premier desktop app framework for Windows anymore. UWP is too limited, WPF is pretty much deprecated. Win32 has a huge learning curve and finding devs would be very difficult. Pretty sad situation.

Maybe their secret plan is to push people into writing web apps with ASP.NET? Event that doesn't work because a lot of people will use Node instead.

I have been developing new WPF applications during the last couple of years.

Those customers were now thinking of eventually start moving into UWP after the Windows 10 migration was complete, so given this, they will continue using WPF.

Also Forms, WPF and EF 6 support are the major roadmap items for .NET Core 3.0

Node is no match against .NET or Java for those that care about performance.

Why not Qt?

True. A while ago I looked into Qt and one problem was that there weren't too many 3rd party components on the market. For WPF and Winforms you can buy extremely powerful components like data grids and tree views (I have been using Developer Express) but I didn't find any for qt.

Checkout QML (as opposed to widgets).

http://doc.qt.io/qt-5/qml-qtquick-controls-treeview.html

http://doc.qt.io/qt-5/qml-qtquick-controls-tableview.html

Here are all the controls: http://doc.qt.io/qt-5/qmltypes.html

Skype has become so clunky and slow lately, so I find myself avoiding it whenever possible. Could this be the reason behind the worse quality?

There's also Qt which they used for OneDrive

Yup, and you don't even need to touch C++ these days. All C# and QML!

https://github.com/qmlnet/qmlnet

(I'm the author)

I’m not sure if it’s true but it seems to me like they replaced their own client with an alternative one they bought from another company, which has parts written in Qt.