Probably because he grew that Aubrey Huff goatee
When the Giants acquired Mike Leake in July, they thought that he would help stabilize a shaky rotation. And after he came back from injury, they were right! Bumgarner was good, Peavy was pretty good, and everyone else, including Leake, was bad. It was very stable. Shoulda been more specific when you met that genie, Evans. Let that be a lesson to you.
But Mike Leake really shouldn't have been that bad. Throughout his whole career, he'd been a decent pitcher in an extreme hitter's park, so it stood to reason that moving to San Francisco, which park factors say turns Mike Trout into a literal trout, would help him out.