For what it's worth, I've been using WindowMaker since the mid-1990s. I hate the paperclip too. That's why I disabled it in 1997, and any application that doesn't go in the dock has it's app icon disabled. Piece of cake. I've never thought configuring Window Maker was complicated, and it's had a GUI config utility for ages.
Over the years I've tried several times to switch to a more, uh, current desktop environment, like Gnome or KDE. I found both to be uncomfortable... and here's the thing. I have three monitors. Window Maker doesn't care about that and doesn't try to micromanage the displays in some weird ways that ignore what my heavily hacked xorg.conf tells it to do. Gnome just goes NUTS.
For example, I currently have the Window Maker Dock on the rightmost monitor. I can move windows between monitors, but when I maximise a window, it only maximises to the screen it's on. Same goes for telling, say, a youtube video or mplayer to go full-screen (in fact, mplayer automatically fullscreens to the big monitor all the way on the left).
This setup with Gnome makes the menubar repeat three times, makes windows maximise wherever the hell they feel like, makes the "taskbar" grab windows from wherever, etc.
Now possibly BusyBox wouldn't have these issues - in fact it very likely wouldn't. And I definitely wouldn't expect you to switch over from an environment you're comfortable with. And the actual benefit of Window Maker, for me, is that I've been using it forever and there's nothing else out there that gives me any more features that I desperately need.