These CoCs are made for the one thing: To keep advertisers or shareholders. Modern Internet works because advertisement. For some anti-logic known only in western countries, hard disk space is getting cheaper so hosting goes more expensive, and pages must rely on advertising to live.
The problem is that, as in old proverb, "appetite grows with eating". Advertising got stuffed to the point of vomiting about 10 years ago and using of adblockers became a habit of many Internet users. So the next thing was running software on users' computers for malicious purposes - doesn't matter is it siphoning data, sending messages or mining cryptocurrency, the idea is the same. Using script blockers is not as popular as adblockers, but I see it more and more frequently.
Now imagine the modern, business and selling-focused Internet trying to place ads in the late-90s "bazaar" Internet of private sites, random early forum or mailing lists discussions and "I-send-this-to-you" pages. Imagine some blog of random "Internaut" writing about everyday things, projects, things pissing off and what he had eaten on breakfast and got parasites, maybe sometimes publishing some works of fiction (or, for maximum fun, a 18+ furry pictures), and then BOOM: a typical modern ad there!
Because you just can't blatantly write in the rules "don't publish negative reviews of companies ....", "advertiser is always right" or even "ostracize people who would then buy more from our sponsors", these codes end with being totally self-negating, but it's not their objective to be consistent.
To keep the advertisers in, it is needed to censor negative reviews and publish the material in the topic which advertisers want. What is against their interests, is (if not self-censored) removed. It has nothing to do with openness and maintaining the community. The discussion is a normal part of the community, and, sorry, if it is a ritual of clapping hands to the ad in the top of page it's not a community but some sick performance of multilevel marketing on the Internet and has nothing to do with discussion.
Of course, as I always write, this positivity and openness is the same "openness" as "healthy" are fast foods in advertisements. It ends quickly when it comes to groups which would spend less money when adding value to community. I have a first-hand experience in it, as recently it focuses on ugly ones.