Well, for one I don't think qtip really got it. If you watch the video documentary, you can even see that Dan Auerbach wasn't that excited with his lyrics.
There is some good stuff there (NOE and RZA for example, and Nicole Wray), and the Black Keys save the day with great production and songcrafting, especially considering they only spent 11 days recording.
I do think HipHopScribe is right though in saying that if those guys focused on an album with a single artist, like Mos Def, and they spent a bit more time developing songs interactively, they could have a very strong album.