In all sincerity, is there anyone really qualified to offer a critique of Dante? I only bring this out to argue that when one critiques Dante, there has to be a trepidation present. What Dante sets out to do in The Divine Comedy is overwhelming in its magnitude. With this, I think any "critique" offered would be more thoughts and insight than an actual "critique."
In terms of the overall tone of Canto XI, one cannot help but notice the strict definition of crimes that are outlined. At the same time, the fact the crimes against neighbor receive the strongest rebuke. This reflects Dante's fundamental belief in social solidarity and in community. This is also seen in the idea of punishing usurers in the harshest way, those who exploit the community for greater material wealth for themselves. Through Virgil, Dante is expressing the importance of community and the need to remove social and political fragmentation from Florentine politics. It is Dante's own experience in the political scene of Florence that revealed itself to be one where individuals not working towards the communitarian or collective good are ineffective.
I think it might be interesting to discuss how Dante views the tale of Sodom. Placing it in the worst part of the circle, Dante clearly makes the argument that societies not geared towards social betterment in the name of God represent the worst in humanity and need to be punished. In this light, the homosexuality in Sodom is seen as antithetical to the nature of social justice. An interesting discussion point would be to see if Dante, cast in the modern sense, actually meant a literal read on "homosexuals" or whether he spoke in general terms about individuals who moved away from the path of God.