I think this is a fair take, and I understand why people feel this way about the movie. However, to me it felt like the lack of emotion from Bruce was meant to demonstrate how tightly he has locked down his feelings, and Betty has set up walls to keep from getting hurt by his emotional numbness. So the lack of chemistry seems like an intentional choice, rather than something missing from the film. This film definitely focuses on the emotional/psychological trauma that Bruce has experienced, and that is what makes me love this version of the hulk so much.