You're the only one who "sees" it because you are mistaken. The controls are still connected, as per the Boeing philosophy. Moving one moves the other, unless s

You're the only one who "sees" it because you are mistaken. The controls are still connected, as per the Boeing philosophy. Moving one moves the other, unless so much force is applied that the link opens (by design, to allow controlling the aircraft if one set of controls is stuck for some reason). This is a pretty clear example of pilot error; they had all the information needed to understand what was going on (and, unlike on an Airbus, the additional information of needing to fight each other physically through the controls), and failed to process that information into a correct understanding of the situation. The fact that these type of events keep happening at Air France tells you it's not the individual pilots, but rather a training / company culture issue.