I'm not sure that's really an argument. Between the start of the Pertwee era and the Davison era there were only about six stories with historical settings and the companions dressed in historical costumes (albeit only briefly in the case of Masque of Mandragora) in all of them.

Several NuWho seasons start with contemporary-historical-futuristic in some combination, particularly when introducing a new Doctor or companion and particularly when trying to provide a jumping on point for new viewers.