I agree that it sounds like a bad idea, but you're just having a knee-jerk reaction. You don't have enough information to make that judgement. How do you know this wasn't a well crafted exercise designed to teach certain elements of social interaction? I guarantee you a good teacher could use a situation like this as a tool to teach the class something valuable.

Hell, it could be an exercise to teach students the dangers of group think. It would be intellectually dishonest of the author to frame the situation in the way that she did, but we have no idea of the context. Did the author watch the whole class and speak with the teach afterward, or did she just observe the class for a few minutes?

Without more context you just don't have enough information to make such a damning judgement.