Characters that have vices and go through actual arcs where they change and become better is... like a standard thing. Easy writing and easy movies avoid turning the audience off their characters because it's difficult to be good at making a movie (as with any discipline, being really good at it is really hard). Obviously, as a writer you want to create interesting characters with tons of depth, something that feels real and flawed, but the difficulty is in not falling too far into 'this person just sucks' AND not going too far into 'this person is infallible'. It's even worse if you attempt to convince your audience of a flaw that doesn't exist. Characters that have no flaws, or that lack real flaws and are just being angsty for poor reasons, are (generally, but not always) boring and uninteresting.

You fixating on the fact that Tony gets even better in the second movie from his starting point, when he's already working through his arc in the first movie, is funny. It's almost like good sequels are meant to build upon and add depth to their predecessors. Yes, the sequel takes some themes of the first and furthers them, unsurprisingly. No, you don't need to wait for the sequel to see Tony begin to change.

You can dislike Iron Man if you want for whatever reason you want, but I wouldn't go around trying to convince others it's a bad movie, especially with the reasons you provided.

Good writing should not turn audiences against characters?