1. I never said I've had unpleasant experiences with code reviews, I said they're too often wielded as a bullying tactic. This is something that can be recognized without actually being a part of the bullying tactic.
Furthermore, your comment attempts to subvert my statement by implying my observation is more about bad personal experiences and less about thoughtfulness.
2. The context for which code reviews has been used is not throwing up some code on a random website and asking random strangers to look over it for educational purposes.
The context is one of a professional environment where code is typically required to be reviewed by another professional before being allowed into the general codebase in an attempt to both educate about the current codebase, catch possible inefficiencies, and to try and maintain some form of quality control with respect to the mechanical aspects of the code.
These are completely different contexts. On a site like Hacker School the worst you're going to get is people mouthing off about shit. In a professional environment, the worst you'll get is fired. Very different environments.