This is even true of my students - I would love for them to critique my teaching methodology and supply me with recommendations of how to make myself a better educator. That being said, when they get feisty in the moment it is not always a good time to get that feedback.
Unfortunately I have found that the official feedback supplied by the School District of Philadelphia is second to many. It seems to me that the observation tools so often used by administrators are implemented to punish teachers instead of help them learn and grow. Education changes constantly and so a teacher needs to be constantly ready to alter his or her style in order to enliven the new generation of classrooms.
Recently I have heard many stories of friends of mine being "observed" and received low marks on a scale that is being used punitively more than educationally (I use quotation marks because I think a 15 minute walk-through is hardly enough time to make an accurate observation of an educator). Also, I am angered by the fact that while the official observation tool has many criteria that describe the wide range of things a teacher has to worry about, these new tools seem to have a very narrow focus, and they are not implemented fairly.
When teachers start thinking of feedback in terms of punishment instead of growth it becomes almost useless. When administrators do the same thing it becomes a grudge. When the state or federal government do the same thing it becomes fascism. We need to seriously evaluate how our District evaluates its teachers.