Given the date, I suspect it was influenced by the Stanford Prison Experiment, which was just three years prior. We now know that Stanford Prison was not an experiment at all [0], but at the time I imagine it was fresh on everyone's minds and believed uncritically.
The proximity to Stanford Prison, coupled with the time (8pm-2am) and her wording ("There are 72 objects on the table that one can use on me as desired. Performance. I am the object.") go a long way towards explaining what happened here. Not that the behavior is acceptable or justified, but that it certainly should not be used to come to any bleak conclusions about humans in general.
EDIT: Also, it's important to note that she had in the prior year performed four different pieces that left her wounded or unconscious. We don't know what they were told in advance, but the audience was almost certainly aware of her MO when they showed up and expecting something intense. That would both have an impact on the kind of person who chose to be there and on their behavior once present.
There was a vogue for stuff about man's innate inhumanity around this time. Stanford Prison Experiment, Milgram Experiement, Cut Piece, Rhythm 0, Sex Raft Experiment etc.
Milgram's experiments were ten years prior. And the interpretation of the experiments' results, that Milgram himself favored, was not about man's innate inhumanity, but about man's ability to perform inhumane acts if ordered by an authority. He emphasized that none of the subjects would willingly shock "the learner" unless ordered to.
More importantly, this is echoed in the other works/experiments. Cut Piece explicitly instructs the audience to cut away pieces of her clothing. The "Sex Raft" was intended to initiate conflict in order to find a resolution but ended out just showing that everyone got along until the "experimenter" deliberately intervened. The Stanford experiment, as said before, explicitly set the "wardens" and "prisoners" up as enemies and instructed them to act hostile to each other.
It seems that the only cases of violence in these "experiments" turn out to be violence performed under explicit instruction. Also note that Milgram's experiment not only has the instructor explicitly insist on an order being carried out but it also removes the subject of the harm by only providing a voice channel whereas the instructor is present in the room with the participant. And a number of participants eventually refused to comply nevertheless.
I go into more detail downthread, but my take is just like the Prison experiment, the takeaway isn't "humans are terrible", rather "humans will do what is expected of them".
Even if the audience didn't know about her and her whole schtick being risky performance art, the table, the items, and the directions set up an expectation of "risky shit is gonna go down". The real question is how far the audience is willing to go in terms of inflicting risk.
The proximity to Stanford Prison, coupled with the time (8pm-2am) and her wording ("There are 72 objects on the table that one can use on me as desired. Performance. I am the object.") go a long way towards explaining what happened here. Not that the behavior is acceptable or justified, but that it certainly should not be used to come to any bleak conclusions about humans in general.
EDIT: Also, it's important to note that she had in the prior year performed four different pieces that left her wounded or unconscious. We don't know what they were told in advance, but the audience was almost certainly aware of her MO when they showed up and expecting something intense. That would both have an impact on the kind of person who chose to be there and on their behavior once present.
[0] https://www.vox.com/2018/6/13/17449118/stanford-prison-exper...