Heh. Martin Fowler concorda com sua confusão sobre o MVC:
I don't find it terribly useful to think of MVC as a pattern because it contains quite a few different ideas. Different people reading about MVC in different places take different ideas from it and describe these as 'MVC'. If this doesn't cause enough confusion you then get the effect of misunderstandings of MVC that develop through a system of Chinese whispers.
No entanto, ele continua a dar uma das explicações mais convincentes sobre o que motiva o MVC:
At the heart of MVC is what I call Separated Presentation. The idea behind Separated Presentation is to make a clear division between domain objects that model our perception of the real world, and presentation objects that are the GUI elements we see on the screen. Domain objects should be completely self contained and work without reference to the presentation, they should also be able to support multiple presentations, possibly simultaneously.
Você pode ler o artigo completo de Fowler aqui .