The reason why it's a good tool is that the person who understands the business problem can try out a few things and have something "working" pretty quick so know that what they want is possible.
Perhaps they then go to the IT team and ask for an application to solve the problem. The following week after an hours meeting they are not comfortable they they have been very effective at explaining the problem to IT, but do now know about having to do requirements docs, user focus meetings, test plans and other stuff they can't quite recall (but have a feeling it involves IT running very fast in races?). It's also going to be surprisingly expensive so they will also need to get budget approval through their management chain. So after lunch they get their spreadsheet out again. They can't understand quite how it worked so they throw it away and write a new version that sort of works.
Biting the hand that feeds IT
