Whether or not the Quran bans representations of the prophet is beside the point. I wonder how Christians would feel if drawings were published depicting Jesus in the same way as Charlie Hebdo depicts the prophet. See, for example, the first two reproduced here: http://www.capjpo-europalestine.com/spip.php?article226. The caption on the first one is: “A star is born!” and on the second: “So is it okay for us to draw Mahomet’s ass?”
Satire, in its origins, was directed at and designed to mock the powerful and to puncture their arrogance. Mocking the religious beliefs of the powerless is not satire but juvenile, gratuitous cruelty. Downtrodden unemployed Muslims living in squalid housing projects in France no doubt have at least one thing in common with Palestinians trying to survive in refugee camps, with no hope and no opportunities in life, and with only their religion to give them some sense of dignity and self-worth. What person of any integrity would want to deny them even that?