Of course, parent's have the benefit of their children's opinion of their teacher to help rate teacher's performance, but that is also subjective. A student may believe that a teacher is too hard on him or her because of the teacher's high expectations. Depending on the parent's educational background, the teacher may be judged as being too harsh rather than being a teacher that is pushing a student to reach his or her highest potential. We would hate to see a teacher judged largely on that minimal amount of contact, especially when judging doesn't seem to be the intent of this initiative anyway. The goal is better communication.
Parents are already welcome to communicate often with teachers.
The rub comes more on how the communication occurs. Many parents don't know the appropriate time to call a teacher or if they are welcome to call a teacher at home. Calls or visits during the day would take teachers away from their primary teaching responsibilities, which most parents are loath to do. School newsletters and mechanisms such as Parent Link are a useful conduit of information. Too often communication from teachers comes only during crisis situations when immediate intervention is needed.