One aphorism has it that culture eats strategy for breakfast. If you don’t get the people across your organisation on side, your change project will fail, no matter how much you throw at it.
When I’ve reviewed major change projects during implement it’s typically hard to find anyone who isn’t on board and committed to making it happen.
When I’ve reviewed other projects, after the fact, when the dust is still settling but failure is clear, it’s often hard to find anyone who didn’t think it was doomed to failure.
Why don’t those sane people speak up before the project is finalised, or as its underway?
This could be because of something called “preference falsification https://en.m.wikipedia.org/wiki/Preference_falsification”, a reluctance to contradict your peer group and call out the problem. If everyone around you is on board, then being the odd one out is difficult. Of course, if everyone around you thinks the same as you, and is reluctant to call it out, then you all end up agreeing that it will fail but unwilling to say so.
If one person is honest, the dam can break. This, really, is the theory behind The Emperor’s New Clothes.