Permacult you are so wrong.
If it hadn't been Charlie Hebdo it would have been some other media outlet or government building or school or shopping mall. Because these people want to commit these sorts of atrocities, they want attention, they want to set people against each other, they are driven by their own ego, their own bloodlust, and the money they are being paid by their support networks.
Charlie Hebdo dissects/pokes fun at all - one particular religion or politician cannot and should not be excluded from that, because then they become "other" - not really one of us. Ironically, poking fun at Islam alongside Judaism and Christianity is a sign of societal inclusion in the minds of the writers and editors.
Finally, your assertion that MNers don't care about what's happening in other countries - to Muslims - is erroneous and offensive. The threads may not be huge or make page 1 of Chat, but then good news stories in other countries don't normally make page 1 of Chat, either.