That is a common interpretation, but it is at odds with the traditional definition of MVC. Decisions, parameter checking, etc. all go in the model in MVC. The controller is just a generic thing that maps input (HTTP requests) to method calls.
Most recent frameworks take this approach, making the model the dumb part (generic object-relational mapping layer) and putting all the application logic in the controller. It seems to work fine. Catalyst's controllers would probably be called part of the model by the traditional MVC definition, but it's just semantics after all.