It could be that he genuinely dislikes Moz's art. I doubt anyone could call "Ringleader" him at his absolute best : its fair to say that Moz does seem creatively in a bit of a rut at the moment. I find the whole racism issue very boring to constantly keep exhuming. Aside from that though, the whole hes-attacking-Moz-because-he's-a-hater/ugly/etc is just a lazy patronising bullshit argument.
Do I dislike the music I dislike because I'm an ugly hater? No, its because the music is, in my eyes, rubbish. And it could be that DQ feels the same way about Moz's music currently. Big deal. Get over it. Moz isnt losing any sleep because of this.