There's a short youtube video from HBR that highlights the difference between strategy and plan. Most people use roadmaps to plan. They want a list of things to do. A strategy can fail. It requires people to place their stakes somewhere, to make decisions under uncertainty, and then to assess their decisions.

This is a low-level problem - its an emotional problem. People don't like to fail. They like to get people excited about the new plan. They don't want to do a retrospective and ask where did we go wrong? who messed up? Even if no one's job is on the line, people just don't like to do this. I've never seen more resistance to any type of process as much as I've seen it to retrospectives.

So it makes sense that people don't want to make a falsifiable bet to begin with. It's uncomfortable.

The solution is leadership. This is one of those things that needs to trickle down from a strong leader that values knowing what went wrong and makes it a low stakes discovery process.