The issues aren't exactly the same for high school students, but when I taught college I really thought the existence of barriers that prevented professors from interacting honestly with their students were a shame. Those barriers took various forms and had various premises. One is the age of legal alcohol consumption. I'm not looking for a return to Animal House era 'get stoned with your prof' parties, but the students drink when they have parties, and professors drink when they have parties, so there's an artificiality about any social activity when they mix. Everyone knows everybody else is just pretending, that it's a fake social event.
Two is the real but overblown fear of inappropriate relationships. Yes professor-student relationships are at best dumb, and of course at worst much worse than dumb, but if you allow professors and students to interact as adults, such things are possible. So there's a tendency not to interact as adults.
Three is the general increase in the degree to which college students as seen as and treated like kids. Unless they break the law, of course.
Anyway, the point is that there's a price to erecting barriers which prevent interaction between teachers and students.
