Because he's in the news.  Jilani, Taibbi. etc

I've always said Chomsky will be remembered for his empiricism as an amateur journalist rather than the arch-rationalism that defines his dated theories of language, but his reportage is pretty basic stuff. He's the Jack Webb of anarcho-syndicalism.  Rationalism wins out in the end, and with it a kind of purblind stupidity. He's the archetypical pedant. There's no way in hell in which he's an "intellectual".

Chomsky to W.D. Rubenstein, quoted in Rubenstein, "Chomsky and the New-Nazis", Quadrant
Volume 25 Issue 10 (Oct 1981)

I see no anti-semitic implications in denial of the existence of gas chambers, or even denial of the holocaust. Nor would there be anti-semitic implications, per se, in the claim that the holocaust (whether one believes it took place or not) is being exploited, viciously so, by apologists for Israeli repression and violence. I see no hint of anti-semitic implications in Faurisson's work, and find your argument to the contrary ‘puzzling and unsatisfactory’ to put it in mildest terms.

Chomsky responding a to question about the quote above. "Circa 1989-1991"

The “statement” to which you refer is a distortion of something that I wrote in a personal letter 11 years ago, when I was asked whether the fact that a person denies the existence of gas chambers does not prove that he is an anti-Semite. I wrote back what every sane person knows: no, of course it does not. A person might believe that Hitler exterminated 6 million Jews in some other way without being an anti-Semite. Since the point is trivial and disputed by no one, I do not know why we are discussing it.

In that context, I made a further point: even denial of the Holocaust would not prove that a person is an anti-Semite. I presume that that point too is not subject to contention. Thus if a person ignorant of modern history were told of the Holocaust and refused to believe that humans are capable of such monstrous acts, we would not conclude that he is an anti-Semite. That suffices to establish the point at issue.

The point is considerably more general. Denial of monstrous atrocities, whatever their scale, does not in itself suffice to prove that those who deny them are racists vis-a-vis the victims. I am sure you agree with this point, which everyone constantly accepts. Thus, in the journal of the American Jewish Congress, a representative of ASI writes that stories about Hitler’s anti-gypsy genocide are an “exploded fiction.” In fact, as one can learn from the scholarly literature (also Wiesenthal, Vidal-Naquet, etc.), Hitler’s treatment of the gypsies was on a par with his slaughter of Jews. But we do not conclude from these facts alone that the AJC and ASI are anti-gypsy racists.

...You ask whether one wouldn’t at least suspect the motives of someone who denies genocide (the Holocaust, in particular). Of course. Thus, I do suspect the motives of Wiesel, Bernard Lewis, the anthropological profession, the American Jewish Congress and ASI, Faurisson, Western intellectuals who systematically and almost universally downplay the atrocities of their own states, and people who deny genocide and atrocities generally. But I do not automatically conclude that they are racists; nor do you.

Faurisson was a Holocaust denier. He wasn't quibbling about methods.

To value the lives of one group over others is bigotry, so we can conclude that the AJC and ASI are in fact anti-Gypsy racists, as we can conclude that Zionists who conquered Palestine were racists.

"I do suspect the motives of Wiesel, Bernard Lewis, the anthropological profession, the American Jewish Congress and ASI, Faurisson, Western intellectuals..."

You're either willing to psychologize or you aren't. To ascribe motives is to ascribe beliefs.

Some people may be so committed to their own innocence that they refuse to acknowledge the historical record. What does that say about them?

repeats: Deborah Lipstadt and other self-hating Jews.