Reading it again, I can see that. However, I personally am a fan of rigorous - not ruthless - code review, the purpose and level of which has previously been explained to a new employee.
Obviously being an asshole is out of line, and if someone is being a dick in code review, that's a problem with the reviewer. But I think that being rigorous about maintaining consistency and quality is important.
Decent positions dont usually need disclaimers. Theres a difference between preaching, teaching, and coaching. Its not obvious that being an asshole is out of line. You make it sound like this mystery of pure "collaboration" is all about giving raw feedback. Raw feedback is inferior to polished feedback. Its just as important to communicate in positive ways instead of throwing this ruthless word around.
Honestly, your problem is that youve approached code discussion from a purely quantitative approach - ability to convince and ability to convey arguments in a persuasive yet unbiased way is huge. No one wants to do things by demand, decree, or just general hate.