Open and honest discussions? That seems like a hill too big to take! It's certainly too big in elementary and middle schools. At that level it's instruction, not discussion. I think we'd need to be pretty careful even in high school.
I've taken college level courses where open and honest discussion has been limited, if not allowed.
The teachers / professors have to be some special kinda leader to provide that sort of environment for his/her students. You and I can name those that did. But they're the exception rather than the rule.