#1 He is a wonderful man manager

Real Madrid's dressing room is littered with the best players in the world who have won all available titles in the world of football.
They are multiple times Champions League and league winners, while most others have won numerous national team titles including the World Cup.
There are few if any other club in the world boasting such serial winners, and with such success comes bloated egos, and winning the respect of or motivating such players is no mean feat.
The Real dressing room is one of the most notoriously difficult in the world, and numerous managers in the past such as Mourinho and Benitez have felt the full brunt of their impact after falling out with key members of the squad.
Handling such egos requires adequate man management, and very few managers possess the requisite skills to do so, as the tactics employed elsewhere such as public criticism of players to boost their performances would land a coach straight on his face at Real Madrid with egg plastered over him for good measure.
Zinedine Zidane is a good example of an efficient manager, as he was able to get the best out of his players without distancing himself from the squad. He successfully convinced the otherwise ever-present Ronaldo on the need for him to preserve himself by rotation, and a lot of his success as Real Madrid coach could be traced to how effectively he managed the egos of his squad (perhaps his status as a former galactico had a lot to do with it).
When it comes to man management, there is perhaps no greater progenitor than Arsene Wenger, as he has achieved great fame for the legendary bonds he formed with his players throughout their careers, with most still maintaining a cordial relationship with him long after their playing days are over.
He cut the role of a father figure to his players, and not on any occasion in his 21-year reign at Arsenal did he publicly chide his player, preferring instead to take the blame even when said player was in the wrong, and this is a factor which could see him endeared to the Madrid players.