Well I was only replying to the phrase "In practice, there is no difference between enforcing rules, and requiring people to agree to rules and enforcing the agreement." - Which is to say there is in fact a difference in the attitude the whole community has towards the rules even if perhaps this is a largely artificial distinction. So yes the rules were set and the students had limited control over how they were written (though a fair amount of control over their enforcement) but I think the attitude a community towards rules matters a great deal.

While I'm not sure about the comparitive morality of breaking one rule vs. the other (though I would lean towards it being worse in an honor code system) I feel more willing to cheat in a system that assumes I will then one that trusts me not to.