Not sure why this would frustrate you. People have ideas all the time internally. I'm going to assume the idea you had was one of many. The issue is getting

Not sure why this would frustrate you. People have ideas all the time internally. I'm going to assume the idea you had was one of many. The issue is getting the real decision makers to buy into it. They aren't going to take the word of someone who works in some division. They want some rigor to it. Bringing in someone who isn't tainted by the groupthink of the company, can actually take a sober view of the situation, has puts some weight to the recommendation.