It has to be one of the more bizarre flights schedules for sure unless they are planning some kind of code share with BACF to operate the AMS route at weekends on their behalf when it's quieter?
On a separate note, I travelled to/from London City for the first time in a while this week and I have to say what a pleasure it was, a seamless travel experience. Every stage of the departure & arrivals process was efficient and easy. London City really have got their model just right for passengers