He almost has as many pinch PA this year as last -- 66 already, through mid-August. As you can see, much of the drop in OPS has been slugging. Despite that appalling .160 batting average, he's still putting up an eminently respectable .364 pinch OBP by having nearly twice as many pinch walks (15) as pinch hits (8).
He's actually leading the majors in pinch walks for the second year in a row. Last year he had 17, and the next-closest was Greg Dobbs, who had 13 and was seen as a major reason the Phillies won the championship. This year, he has 15; the next-closest is the Phillies' Matt Stairs, who has 8. (Dobbs has fallen off even more than Norton; his pinch OPS this year is .484, in 50 pinch PA.)
Obviously, a walk is NOT as good as a hit; a walk can't score anybody from second. But it's a whole lot better than an out. As soon as Norton loses the ability to work a pinch walk, he'll be completely useless as a baseball player. For the moment, though, he has at least one valuable skill: the ability to get on base off the bench. Could Brandon Jones (or even, shiver, a September Jason Heyward) put up a better OPS? Probably. But Norton hasn't been as worthless as he looks at first blush.
Never thought he was a league leader, did you?