The defense has been bad, a lot of this has had to do with Trumbo playing first over Albert, Shuck and Harris getting significant time with Aybar and Bourjos hurt, Callaspo's inexplicable shityness, and Chris Iannetta.
That said I think the numbers overstate the issue. The pitching has been sooooo bad that the stats think everyone sucks. The stats are going to look at where balls are hit, whether they are line drives, ground balls, fly balls and what not and expecting everything else to average out. Ultimately the stats aren't quantifying just how hard some of these balls are coming off the bat, and just how tough some of these plays have been. I don't think it's a coincidence that our horrible pitching has coincided with inexplicably bad defense.