It also made the experience richer for people who cheated witih impunity.
I will never forget being in high school and seeing so many classmates cheat on homework and take-home exams, yet raised their hands with ease to give the honor code pledge. It was a farce. Please don't read my personal anecdote as doubt that honor codes can work.
I'm not even sure I could have answered you at the time. In my memory, it was mostly students promoting the honor code. But I have to imagine that the university was quietly doing things to keep this going.