Jesus picked males because in his culture women would not have been accepted (though he had women who traveled with him and worked with him). Because Jesus rode a donkey, we should all ride donkeys or because Jesus wore sandals we all should wear sandals? You are correct to say males priests only is a "tradition" and traditions can be changed as the times change. Continuity sometimes stifles growth as the all male priesthood is stifling growth in the RCC.