For an app meant for the creative types, GIMP sure is ugly.
I also thought we were over mystery meat navigation, but it seems to be going strong at GIMP. Not only does having icons for each tab make it look incredibly busy, but it also makes it harder to learn and wastes a ton of screen space. I can't see a single benefit other than it doesn't look like Photoshop.
I wonder how hard it would be to redo the entire interface from scratch. I would love to design it, but no way do I want to navigate their bureaucracy.