Snarky response is 'you can't teach height, passing, or winning either apparently'.
But in all honesty, Ben Gordon is only 28, its easy to forget that. His shooting % was roughly the same as it was during his good years in Chicago, but his rate of scoring dropped significantly. And I don't mean just his points per game, his rate of scoring per minute on the floor dropped, which isn't a good thing in any world, but its also a bit confounding. His usage (amount of plays that end in his hands, roughly speaking) is pretty close to where it was his last year in Chicago.
I don't know what it adds up to, but its a strange situation.