Playing behind that offensive line? I wouldn't judge him too harshly.
While the line has "only" allowed 10 sacks on him, that number is deceptively low because Moss manages to throw it away most of the time, and still ends up taking a hard hit. That line can't pass protect very well at all, and they are (were) lucky that he has a quick release.
He has been battered silly this season, and the offensive line isn't getting any better.