Understanding why the apology took this long requires looking at what was happening to the Academy as an institution during those years, and what forces finally produced a reckoning.
The Academy was founded in 1927, primarily as a mechanism for the industry to manage its relationship with its labor force. Its early history was characterized by the same indifference to representation that Brando was protesting in 1973. The membership was overwhelmingly white, overwhelmingly male, and organized around the values and aesthetics of Hollywood’s studio system. The awards it gave reflected its membership’s tastes: European-American stories, European-American casts, European-American directors.
This did not change dramatically in the years immediately following the 1973 ceremony. The rule change that ended proxy acceptance was the most visible institutional response to the event, and it was a defensive move rather than an engagement with the substance of Brando’s protest.
The slow diversification of the Academy’s membership over subsequent decades was not a direct consequence of the 1973 protest. It was the result of sustained pressure from multiple directions: the increasing commercial significance of films made by and for non-white audiences, the organization of advocacy groups within Hollywood, and the periodic public controversies about the overwhelmingly white composition of the nominations that crested in the #OscarsSoWhite campaign of 2016.
The #OscarsSoWhite campaign — in which Black actors and directors were largely absent from the 2016 nominations, prompting a boycott by Jada Pinkett Smith, Spike Lee, and others — was a significant inflection point. It produced a specific institutional response: the Academy committed to doubling the number of women and minority members in its membership by 2020. It created new voting blocks and new structures designed to ensure that the membership’s demographics were less exclusively white and male.