The business logic belongs to the problem domain and everything that belongs to the problem domain goes to the model in MVC.
The controller should be responsible for passing the data from the model to the view and from the view back to the model. The controller is therefore the bridge between what the user interacts with and how the program models and stores the state of the problem. The plumbing, so to speak.
The key here is the distinction between the business logic and the plumbing logic. In my opinion, what the autogenerated Account Controller does is mostly plumbing, not really business logic. Keep in mind that the plumbing logic isn't necessarily short at all, so you don't need to impose artificial limits (like "X number of calls at most in the controller").
