But for all the hard-hitting moments of the monologue, it also defended the ceremony. Rock took several swipes at critics, notably at Jada Pinkett Smith and the #askhermore hashtag, which protests the red carpet focus on what women are wearing.
Another of his statements showed how difficult defending the ceremony without using the rhetorics of racism can be. In the 1950s and 1960s, he said, "black people didn't protest because we had real things to protest at the time. We were too busy being raped and lynched to care about who won best cinematographer. When your grandmother's swinging from a tree it's really hard to care about best documentary foreign short."
Embedded in this stark and important indictment of historical reality is what Eduardo Bonilla-Silva, a leading theorist of 21st century racism, terms "minimization". This happens when the harm of contemporary racism is downplayed because the situation was worse in the past.
In defending the ceremony, Rock's monologue implies that race-based violence in America is a thing of the past, and that the racism and exclusion embedded in the Hollywood film industry are somehow not quite, as he termed it, "real things to protest".
Civil rights leader the Reverend Al Sharpton and the crowd of protesters he addressed on Oscars night know that entertainment does matter. Words are connected with acts, sometimes violent ones.
Sharpton said "this will be the last night of an all-white Oscars." The protesters held signs and chanted slogans of the Black Lives Matter movement, which was first organised in 2012 in response to the killing of Trayvon Martin.
Lack of representation on screens and in the film industry reflects much wider imbalances of power that reach right across culture and society, and not just in America.
Hollywood's lack of diversity runs much deeper than just its flagship awards ceremony and includes under-representation of all racial minorities, not just African Americans, as well as women, LGBQTI people, and disabled people. As Stacy L. Smith, Director of the Media, Diversity, & Social Change Initiative at the University of Southern California told The Washington Post: "The only group thriving in film is white, straight, men."
Given that the Oscars celebrate the American film industry first and foremost, and are clearly tangled in US politics (US Vice President Joe Biden appeared on stage there), one might ask why Australians should care about the question of representations of race in Hollywood. (Indeed when I wrote on this topic in the past, I was asked that very question by people commenting on my article!)
There are multiple reasons for Australians to be interested in what happens in Hollywood. For one thing, we tend to celebrate when Australians win awards. This year's success, Mad Max, Fury Road, was being trumpeted in the media even before the ceremony was over. Taking on only the good elements of the Oscars is disingenuous.
The Australian film production industry is closely tied to Hollywood, with multiple blockbusters including Thor: Ragnarok and Alien: Covenant (formerly Prometheus 2) set to film here in 2016.
Local film culture and industry are not completely separate to Hollywood. All of the top ten grossing films on Australian screens in 2015 were made by Hollywood studios.
Also, popular culture is an important way that people learn about the world, especially aspects that are outside their own immediate experience. Seeing the same kinds of stories and people over and again limits what we can know and imagine.
This is true for people of colour, for disabled people, for LGBTQI people, and for other minorities whose stories are only infrequently told in any form of mass entertainment. Tanya Denning-Orman has written eloquently in The Guardian about the need for more diversity on our screens. As she says, "black faces seeing black faces across the media is essential".
Films validate people and their stories; making a movie about someone says that on some level they are important – not just to the individuals who see a movie, but to the culture in which it was made.
When the entertainment industry recognizes that stories matter, first by telling them and then by giving awards for excellence in the telling, the impact is at once much bigger and much more personal than saying "it's just a movie" suggests.
Rock's monologue was the most politically engaged and confronting of recent years, and the Oscars have come a long way from Seth McFarlane's 2013 opening song "We Saw Your Boobs". But the entertainment industry still needs to acknowledge that what it does is important, and act accordingly. And so do we as its audience.
Image: Reverend Al Sharpton outside the Oscars ceremony. Image credit: Reuters