After childhood, telling is often interpreted as an attempt to control. Whenever we tell people how to do something differently, we convey a subtle, negative message that the way they have been performing is wrong or not good enough. This often creates defensiveness. Telling implies that something has to be changed.
People love to control but hate to be controlled.
This is especially true for adolescents who are attempting to assert their independence. Telling is akin to rewards and punishment in that all three are external attempts to change behavior. Responsibility can only be taken, not told.