Not just incentives, but also cognition - when you change the presentation of the problem, you change the way people think about it. I think this is the reason

Not just incentives, but also cognition - when you change the presentation of the problem, you change the way people think about it. I think this is the reason to build prototypes that you can play with - you really will see things differently. And (hold the hate) obviousness in patent law takes this into account, by evaluating it with respect to the publicly known state of the art - but if you have iterated a few prototypes then you have private information. You got data that no way else has; in addition, new ideas came to you for the next prototype. Each step may have been pretty obvious to you - but from the perspective of someone who had not yet even seen the first prototype in chain, you can seem like a magical genius.