Challenge assumptions

Assumptions can become damaging if left unchallenged. The advantage of a map is that it's visual and everyone can understand it, so assumptions can be more easily challenged (e.g. why are you custom-building a commodity? Why are different departments focused on meeting different needs for the same customer?). Challenge leads to better understanding, learning and a quicker MttR (Mean-Time-to-Respond) to changes in the market. Therefore, challenge should become the duty of everyone in the organisation. The greater diversity of perspectives you can bring to a situation the more likely you are to spot weak signals of opportunities or threats earlier than rivals, enabling you to exploit them or course correct accordingly. 

It shouldn't matter if it's someone's pet project, everyone needs to openly and honestly challenge assumptions, but in a structured way (i.e. using PowerMaps) so learning can be accelerated and action can be taken BEFORE more resources are poured into it. But note: any form of retribution against someone for challenging assumptions is a deadly sin that will harm your company by making it more stupid, weaker and easier prey for predators in your industry who aren't afraid to challenge the status quo. 
Organisation Responsiveness