I don't think Charlie Hebdo was really agressive or disrespectful
The world is political. The world is religions, wars, disagreements, economic exchanges, beliefs. Drawing this pictures is a political action. It is : "I want to see the differents structures of the world to understand it"
I personally thing that this pictures are funny, not all but they are not disrespectful. I see everyday peoples of different countries and beliefs. When we talk about that, a lots of them explain that it is funny for them to.
Maybe it's just that we draw and see the picture on a different way