Because it's not all to his credit. It's flukish to have a HR/FB rate that low at GABP, the same way its flukish that Cueto has that low of a rate. If he was getting a ridiculous ground ball rate, I would say, "he does a good job of keeping the ball on the ground, and in the ballpark." However, he doesn't do that. He has been giving up plenty of fly balls, but he has a flukish HR/FB rate.