I haven't watched any games since he's been called up so I don't know what his swing looks like, but I don't think you can completely determine he is a really, really bad hitter just based on his stats in AAA this year. Before you jump to conclusions I'm not saying he's good. I'm arguing with your methods for determining if he's good. As you said, you have no opinion on his D, so you're saying he's a terrible player based on AAA wRC+.
I agree with Caper that he would be a good new version of McCoy next year.