Wasn't the only reason he wanted to be a Jedi Master because he wanted to get into the archives to see if there was a way to save Padme? Like, he wasn't just mad that he was passed up for a promotion.

In the novelization yes, but not in the movies, where it was shown as nothing but impatience and frustration at not getting the recognition he felt he deserved.
Not sure how canon those are anymore, though, considering how basically everything except the movies were declared non-canon by Disney.