I haven’t seen it but what you say echoes reviews I read. They say Amy Adams overacted.
The A to B was....he joined the Marines and with the GI bill he could afford college.
The film being "Based on a True Story" about J.D. Vance's teenage years the way Mommie Dearest is "Based on a True Story" about Christina Crawford's childhood is a apt comparison, IMO.
Interesting, some FReepers refuse to see the film because Ron Howard directed the movie and they think he put a "liberal agenda" in the movie. Howard claims to be an apolitical independent (he's not, he's a hardcore lifelong Democrat), but there's no "liberal message" in the movie. There's not a conservative message, either (supposedly the book has some conservative "pull yourself up by your bootstraps" message but that's not conveyed in the film AT ALL). It's just a bad movie that flopped, period.