The people complaining are really full of shit. If anything, it's less plausible than that repellent anti-Tolkien rant by that stupid bitch a few weeks ago. The passage about Judas being chewed is interpreted liberally as "anti-Semitic" - I wonder if that makes Dante anti-Italian as well considering the other two traitors being chewed are Cassius and Brutus? Essentially, the anti-Semitism is simply in the fact that Dante has the betrayer of Christ in the maw of Satan, and these dipshits have extrapolated that to blanket anti-Semitism (I wonder what their opinion of the New Testament is?).

The Muhammed phrase is cited solely because he's rendered in half the same way that all sowers of dissension are, and that some comparison is made to a wineskin, and wine is "not permitted in Islamic law". That is extrapolated to show "a lack of respect for Islam", despite the fact that, as you pointed out Averroes is in with virtuous non-Christians and other Islamic influences were brought to bear, and that, given the times he was writing in, Dante is actually not all that anti-Muslim.

Then there's the fact that the sodomites (homosexuals) are being punished - is that at all surprising, given that homosexuality is explicitly listed as a sin in the Old and New Testaments? While modern Christians are moderating those lines, it is hard to escape the literal impact of the statements, and Dante can hardly be faulted for listing as a sin something that was considered a sin in the world in which he was writing. Despite that, there are many scholars who feel Dante may have had some homosexual tendencies or at least sympathies, given that some of the most sympathetic people in Hell are the sodomites.

Essentially, they're grasping at straws just to get some controversy. People like that deserve to be dumped into raw sewage and forgotten.