The biggest problem is that MS seriously dropped the ball. There was never a developer friendly API like Qt or Gtk for windows, MS wen't down the drag'n'drop to

The biggest problem is that MS seriously dropped the ball. There was never a developer friendly API like Qt or Gtk for windows, MS wen't down the drag'n'drop tooling route instead. The other problem was that everything was grey boxes by default and almost no apps stick to the native look and feel, let alone allow themeing. This is even true of most MS apps like office and internet explorer. Contrast this to linux desktops where you can knock out applications fairly easily and it uses the local theme by default. They made it easy to do the right thing so most apps do the right thing. For an example, here is a todo list I threw together: https://gitlab.com/flukus/gtk-todo/blob/master/main.c https://gitlab.com/flukus/gtk-todo/blob/master/main.c . I just define my app, I don't do any theming, I don't worry about font sizes or color scheme, I just use the defaults that the toolkit provides and when I open the app it looks like every other gnome app. This is what windows was and probably still is missing. And the problem seems to be getting worse, see the awful background image in the windows 10 email client. Aside from that, mobile UI's are simply much easier than desktop UI's. There is a lot less variablity in screen real estate for one, everything is full screen all the time. The don't have nested menus, they don't have accelerator keys, they don't have to (can't) display complex data, they are simple out of necessity.