The programmers insisted on inserting a confirmation dialog box, resulting in a 2-click interface. Even Amazon's president had a difficult time convincing the programmers to remove the confirmation box. There is a need for professional interaction designers. Programmers are concerned that if someone else does interactive design, they won't have anything interesting to do. Cooper argues that interaction design is only a small part of software design.
Interaction design is limited to the interface, so programmers still do a great deal of design work.
Another common problem is prototypes turning into products. Prototypes are only supposed be created for demonstration and proof of the concept. But sometimes they work too well, and someone decides they should become the final product. In most cases, the prototype is made out of spit and bailing wire and does not have the right foundation or architecture for a full-featured system. In reality, it is cheaper and quicker to throw out the prototype and reprogram the actual product from scratch.