Ok OP, elucidate me, I'm going to break it down as simple as I can.
You said your issue with this was that it was virtually indistinguishable from actual hate speech because no one would get it. This is patenly false as you can see by the reactions in the thread. Plenty people got the point just fine.
Which means your issue is actually with a small-subset of idiots that would interpret it as something that reinforced or celebrated their racist views. You don't care about how everyone else views it, just the view of that stupid small subset of people.
Similarly, The Onion and Colbert, for example, rely on satire a lot. Some of that satire is lost on people, which is why racists share posts on facebook to complain how horrible immigrants are by sourcing onion arcticles, or people that believe Colbert is a die-hard republican. Do you take issue with Onion and Colbert because some dumb people don't get what they are doing? Because that's exactly what you've been arguing. Aside from the quality and crassness of it, what makes Charles Hebdo such a different thing to Colbert or The Onion? Or do you also believe that those are terrible and harmful examples of satire because some people misunderstand it?