I can't really explain why, but looking at Avalonia's demonstration videos I don't like the UI controls in Avalonia.Themes.Default. They remind me of what you might end up with if you designed controls manually in e.g. a Flash app - it doesn't feel like a desktop app UI kit.
It's a bit of a shame, because I strongly suspect the theme is easily overridden. It just needs a designer to make a consistent set of controls.
The themes can be easily overridden indeed. Here [0] is example of custom theme applied. For sure the project would really benefit from some pro designer help.
It's a bit of a shame, because I strongly suspect the theme is easily overridden. It just needs a designer to make a consistent set of controls.