I liked him only when he was being an asshole, but there was nothing to bond with in the end.

>There's really just no good way to make a hero story about a
>character who was never meant to be a hero in the original
>film in the first place. The whole message of Wizard of Oz is
>that hero worship is pointless: you possess what it takes to
>achieve your goal, and you have all along.

They made a half-assed attempt at pulling it off though, and it could have worked had they amped up his inner Scrooge McDuck. He was an asshole, but they merely touched on his innate greed instead of exploiting it. I agree that Glinda let him know she knew he was a fraud far too early in the story for there to be any weight, and that compounds the lack of any real malicious intent on his part.

You actually laid out a great roadmap for making it work. In the end, Oz works as a hero only if used as the vehicle for inspiring his people to believe in themselves, as he ultimately facilitates in the original film. It's easy to let that get to his head over time to where you have this curmudgeon we see in the original.