One-side cultural change is impossible. If increased agility requires increased trust, it must be equally increased on both sides — the product team and the business team. This is unlikely to happen if any of them has a great experience of compromising opponents, which is always present in organizations with a long history.
High trust inherent to the small groups. Therefore agile principles are naturally accepted in start-up teams and just as naturally rejected in the corporate projects, despite declaring it. If one side doesn't trust the other, no matter what is said, only waterfall works between them.
The rejection of agile methodologies, actual but not called so, can be blamed, but can't be fixed in the most of large organizations.