I don't want to credit hitting coaches, as that is the most overdone comment. I will credit an idea though -- there's too much of a downside for him when he's constantly trying to hit to all fields. Alex doesn't have to be an All-star hitter, just take it into right field when the opportunity is there.
I'd rather he be an overpay and do what he's best at than try to justify the contract. If he's fine defensively, and maintains that career OPS, I don't see why people consider this the worst overpay of all time.