My first impression about reading about it ("Skinny Controller, Fat Model") was that it is a basic of Object-Oriented Programming. If you are familiar with Object-Oriented Programming practices such as small method, refactoring, Design Patterns, your code naturally becomes what this article is proposing. Especially, my impression is that if you are doing Test/Behaviour-Driven Development, it is even difficult NOT to become as proposed.
What I liked about "Skinny Controller, Fat Model" is that it is explaining the best practice from the different perspective and with the simpler expression. You can reach the same code either following the basic Object-Oriented Programming practices or following "Skinny Controller, Fat Model".