Fair enough:
Which is exactly the point. Poor use of rotoscopy is hell on the eyes, but it can be used to great effect.
Don’t be so quick to judge Waking Life if you’ve only seen a few clips-- the “rotoshopping” was done by a number of extremely talented artists, and they do a great job of exaggerating and augmenting the scene. It is most definitely not just tracing – especially with some of the more manic characters. Facial expressions and physical gestures are sometimes hugely exaggerated, and extra elements are added in.
Don’t misinterpret me, I’m not making a case for “Rotoscoping is great!” Anybody who’s seen Heavy Metal knows that most of the time it sucks like Saucy Nancy. Waking Life, contrariwise, is great. Check it out sometime.