I like the thought. IMHO IDM is capable of accelerating decision-making in a lot or even most (business) situations - BUT would you consider "negotiating" with your wife or children like this? And if not, why would you hesitate?
There are situations where you're better of with consent (/majority) rather than lowering concerns of stakeholders. Often IDM does not build trust between stakeholders, but sometimes you need trust, sometimes you want everybody (or at least most) in the same boat and have their committment - then it's worth going the extra mile rather than just cut the path short.
Architecture might be a very good example. What if people loose faith in product because to many decisions where made against their "gut-feeling"? Will they loose interest because they don't feel like its their product anymore?
We used IDM for other situations too (architecture / tool-decisions) and it worked well. Only problem we experienced was because there are mostly no roles and no explicit purpose in the context testing of objection was not that easy