The fallacy there is that you're equating complexity with confusing design. It's possible for a well-designed diagram to convey complex information in a clear and cohesive way. This one does not. If anything, I'd say the problem is that it's too simple -- it lacks enough information to get things across clearly. For instance, in what order are we supposed to follow the symbols? What do the different colors and types of link represent? Why do some of the arrows go both ways?