The author doesn’t really cite any evidence for this conclusion and that he cites the idiot and asshole Jacob Canfield discredits his article even further. Here is the level of Canfield’s argumentation:

Even in a fresh-off-the-press, glowing BBC profile of Charb, Hebdo’s murdered editor, he comes across as a racist asshole.

Charb had strongly defended Charlie Hebdo’s cartoons featuring the Prophet Muhammad.

“Muhammad isn’t sacred to me,” he told the Associated Press in 2012, after the magazine’s offices had been fire-bombed.

“I don’t blame Muslims for not laughing at our drawings. I live under French law. I don’t live under Koranic law.”

He called a just murdered man a “racist asshole” based on a passage that doesn’t contain a single hint of racism. That’s what the Slate guy calls “eloquent”.

CH was a left-wing magazine that positioned itself as anti-racist. Now, I’m not taking a position on whether it’s true or not, but it was certainly anti-National Front.

True, some American bloggers have posted their willful out of context misinterpretations of some of the cartoons, but this only showed their cultural ignorance, nothing else.