The steep angle of the windshield was my first thought, but I hadn't known of similar complaints from Jeep owners at the time, so I immediately decided to blame the glass. But it makes sense, and the auto glass guy who fixed mine told me he sees a LOT of Jeeps, and confirmed it's definitely the angle of the windshield.
I guess it's one of the prices you pay for owning an FJC! (or a Jeep, or a Scion xB for that matter)