model -> observer -> view -> controller -> model ->

I'm reading on design patterns and while authors agree that observer pattern is cool, when it comes to design, everybody talks MVC.

I'm a bit confused, MVC diagram is not circular, isn't it natural for code flow to have closed topology ? Why nobody talking this pattern:

model -> observer -> view -> controller -> model -> ..

If view needs controller, then model needs observer, no ? With Object.observe() coming with next JavaScript version, what is wrong with such a pattern ?