There are two reasons for that both psychological. First is the security blanket like a child of the old habit of previous aircraft. Second also is the comfort factor of doing something even when it means undoing. They feel comfortable setting and flying extra 20kts when it may not be really required and feel uncomfortable with same extra 20kts added by GS mini when required. They must not be allowed to do so. Boeing guys have habit of flying excess speed. Airbus must be flown Airbus way.
Last edited by vilas; 10th Jun 2019 at 18:22.