Nue's hair actually is that long, though. It's just styled off to the side, so it's difficult to see in her ZUN-art...
Also, speaking of TV Tropes... I'm somewhat ashamed to admit that most of the nicer things about the Watatsukis in the Touhou Character list were added by me (I'd had enough and just wanted their article to be a little more impartial)... And slightly less ashamed to admit to adding Badass Normal to Yumemi~