Because you need to know what events you care about.
If instead you declaratively define the state of a component via a shared model then you don't have to care how something was updated, just that it was. Any new way you come up with mutating the object will be reflected in all of the components that watch the object.
If instead you declaratively define the state of a component via a shared model then you don't have to care how something was updated, just that it was. Any new way you come up with mutating the object will be reflected in all of the components that watch the object.