I think it's possible that JPA ups his walks over the course of time as he goes on in his career, but even if he does... he's still very bad defensively at the position he plays, and a few more walks per year isn't going to change his overall value because of that fact. As a catcher, his D will also improve, but even with slow marginal improvement over time, he would only get be an average defensive catcher by the time he's 30+, at which point his bat would go south and he'd still be an overall liability as an everyday player.