E.B.'s letter does indicate a teacher who is insensitive in dealing with her students but, as with other accounts of this type, is sort of one-sided -- the problem with accounts like this is that they are never vetted; there is no follow-up and, in this case, we are limited to the perceptions of a 17-year-old who had her own concerns that day. The focus of the letter may be this person's insensitivity, but it is only on your site because of the background incident, about which the author knows nothing except the names of the participants -- it would have been more effective and perhaps made her point better if she would (or could) say why the student in that office ahead of her was being punished; I'm not saying that it was necessarily justified, but the letter is a bit unfair to all concerned, really, in terms of what it doesn't have. The author may be right, or she may be wrong -- we have no way of knowing.
It seems you are chiding us for failure to give equal time to the perpetrators of acts of sadism and violence. Your characterization of the teacher as being "insensitive in dealing with her students" merits an award for Understatement of the Year. Would you be as concerned, I wonder, for fairness to wife beaters? After all, one might want to know what the wife had done to warrant such treatment. In this case (paraphrasing your letter), we are limited to the perceptions of the wife who had her own concerns that day.
Project NoSpank was not set up to give equal time to those who already have virtually unchecked power over the defenseless including the right in 23 states to batter them in the pelvic area with a flat wooden board. Teachers belong to powerful unions that will vigorously defend even their most dangerously incompetent dues-paying members. Abused students have no such organ. They have no platform for expression nor any means for redress. When some finally find their voice, and report what was done to them, they deserve the courtesy of a fair, full hearing without being heckled.