eh. I think the article is attacking a straw man. They're free to call recently slain people racist assholes, I personally don't even think that's tasteless. But I think jumping to the conclusion that this outpouring of support for the magazine is condoning their messages and cartoons is the complete opposite and wrong one to draw. supporting the magazine under the name of "freedom of speech" isn't saying they agree with the message, it's saying everyone should always have access to the neutral space that is free expression—particularly if you disagree with them. and likewise, freedom of speech also means that Muslims can access that space and provide their own rhetoric in retort.
freedom of speech is, by definition, the very mechanism by which criticism can occur. as an argument, it's nonsensical.