This whole debate about cartoons/movies is missing the big picture.
As many commentators have noted, these protests are an excuse to vent latent anger. In the same way that, when couples fight, the reason is rarely the trigger event itself, but a host of underlying issues, these protests are a window into the underlying anger about Israel, Iraq, Afghanistan, various anti-Muslim laws in Europe, double standards in Western media, etc, etc.
Some of these grievances are legitimate, others are drummed up, but the depth of this anger is undeniable.