Throughout my time in software this myth has been pervasive. Usually the "smart guy" is highly technical and no one can do what he can do. (It's always been a dude in my experience.) Often this guy is highly responsible for the initial demo of a application or tool. He is perceived by the other technical people as possessing code writing skill that is unmatched. Management is often afraid to lose him and just afraid of him. He isn't always boorish but if he is, that's okay.
He is also the guy who single-handedly sinks everything else but that demo that he built.
He has little to no understanding of the more important idea that it is more important to sell the application and support the customers who bought it in the long run.
You certainly need the demo if you are a start-up looking for funding. And you need to the demo to justify the feature in a more mature application at a big company. The "smart guy" is crucial and it's not his fault.
At some point, what becomes as important or more important than the central core feature?
Most of this stuff isn't "technical" or "sexy." It's just basic business. Yet, software companies trip over this stuff time and time again. The first software company I worked for made this mistake back in 1986. It hasn't ceased yet.
I look at it like this. Eggs are a key ingredient in pastry. You also need butter, flour, sugar, baking powder, cocoa and other stuff. Without eggs you don't have an all important protein binder. However, if you use rotten eggs, no matter how good you prepared the pastry dough, no matter how well you cook it, it is still not edible.
It's not the smart guy's responsibility to know all this stuff and care for it. He has a job to do like any other job. His actions must be considered in the greater whole. He has his responsibilities to report his progress, too, and fit in with the greater good. However, management must let go of the awe of the demo and put all of the efforts into a context that is fair to everyone and continues the going concern.