[DrJokepu]

In my experience, once your application grows large, if there is a clear path or direction of data flow you tend do have less bugs. If your application has N components and you don't have a single data "bus" you have N * N possible interfaces between the various components hence N * N opportunities to introduce bugs, while if you have a single data bus, you only have N interfaces and less opportunities to introduce bugs as a consequence.

Obviously in practice not all components will interface with every other component, but there is still a lot of complexity added by arbitrary communication between the various components.