Why? Consider that on projects where the domain problem is simple yet the user requirements are complex, it may make more sense to optimize speed of developmen

Why? Consider that on projects where the domain problem is simple yet the user requirements are complex, it may make more sense to optimize speed of development of the client. a webmail client would be a great example of this. The server side is really a small problem, excepting for performance. However, getting the client right is why people still use gmail.