It is hard to imagine that there is anything else there at this point. It does not seem like he has the physical hitting tools to be better on offense.
He might be able to squeeze a few more wOBA points out of his skillset with minor changes... maybe. But hitting just looks "hard" for him all the time. A lot of his walks come from being passive and getting lucky, for example, and not really from having a good eye (IMO).
A lot of people are mad he isn't as good or better than he was in Arizona but with his swiss cheese swing and mediocre eye, I wonder if we should just be happy that he's a league average (ish) hitter still?