Because millions of years ago we traded in high levels of indepence for high levels of compliance in our species. https://www.youtube.com/watch?v=mOUEC5YXV8U Chimps are our closest animal relatives, they have retained high levels of independence in their species. A chimp is not compelled with compliance the way humans are. A chimp will do whatever it wants whenever it wants. Humans on the other hand, somewhere along the way we went through a massive evolutionary change that forced us into a highly compliant species. We are closer to a herd animal than a chimp in terms of our hard wiring at the nervous system level. It takes A LOT to stand up and combat inherent human compliance levels. Even minor conflict will really wear on us. If you re in the right place in the human hierarchy, you can make humans do anything that you want, including kill them selves. Add to that that I don't think humans are allowed to tell the truth in human interaction because most of our communication is based around signalling which groups we are allied with for survival reasons and even minor amounts of human interaction over a long enough period will tire us out.