People keep forgetting Wish still exists and many Open Source GUI apps are scriptable with guile.
And the reality is that Linux desktop environments are skins. The widget toolkit is almost always a separate project. This is becoming even more pronounced with eg Wayland where the compositor just hands the client a surface to render its UI on and knows absolutely nothing about widgets or fonts (not that people have been seriously using those features of X11 for a while anyway.)
And honestly this is preferable. It looks hideous but it's much more pleasant to use. CWM doesn't have many features but the few it does have (such as the regex window title search) I so dearly miss on much nicer looking UIs (like OSX on my work computer.)
And the reality is that Linux desktop environments are skins. The widget toolkit is almost always a separate project. This is becoming even more pronounced with eg Wayland where the compositor just hands the client a surface to render its UI on and knows absolutely nothing about widgets or fonts (not that people have been seriously using those features of X11 for a while anyway.)
And honestly this is preferable. It looks hideous but it's much more pleasant to use. CWM doesn't have many features but the few it does have (such as the regex window title search) I so dearly miss on much nicer looking UIs (like OSX on my work computer.)