I don't presume to judge the quality of Dave's output, but I've always enjoyed his sets, and he's been great to work with on shows. He's been able to support himself with things like the K-Fed gig, commercial remixes and ringtones, while continuing to DJ and make tracks.
If people want to complain about his work that's fine, but he's pieced together a living out of the opportunities presented to him, and there's no inherent shame in that. We all got to pay the bills. And frankly, if someone came to me and gave me a sack of money and said "Make a record with Kevin Federline," hell yeah I'd do it. It would be a surreal experience, and it might be fun. It's honest work that hurts no one.
