Does anyone have any idea about why these rules would be secret?
The only thing I can think of is that YouTube is not confident in their guidelines & categorization, and does not want to defend these choices publicly.
The reason to keep them secret is because they are very clearly not rules. There's nothing too specific about it, and so there's going to be a fair bit of actual judgement calls being made. If they publish the rules, then they become actual rules instead of content moderation guidelines and they lose their freedom to interpret those rules based on context.
Don't work for youtube, but I'm guessing they would be secret for a couple of reasons.
1. If made public, people could post violating content and work around it by making sure they won't get flagged with carefully crafted thumbnails, content etc. Ex: Take a look at the 'Nudity' section. There are examples of 'Partial nudity' in which a guy wearing underwear is deemed inappropriate because it looks 'Vulgar'. So one could, in theory avoid such thumbnails, and still post vulgar content in the video and get by their censors.
2. It would also open Youtube to criticism, just like the Facebook breastfeeding content was, a whiles back.
I think you're spot on. I manage an online game, and we don't have rules. We have somewhat vague guidelines, and moderators we trust to enforce them.
Rules are open to arguments, and with dozens of bans/appeals a day, it'd be ridiculous to do that. We tried strict rules, and they are both too restrictive and ineffective.
Humans need to make judgements, and guidelines give you the latitude to do that.
1. Many very popular YouTube videos (eg brosciencelife) are profane - the Dom Mazetti character is a douchebag - and people come to YouTube to watch them.
2. The guidelines seemingly allow what would be considered hate speech if the topic is women's equality.
The only thing I found confusing was the unwanted creators for the alleged secret meeting. GradeAUnderA is hilarious[0] and has a few videos that point out the drama in YouTube. Keemstar is toxic. I don't know about the others and I can name quite a few channels that should be on YouTube's unwanted creators list (if such thing existed).
The only thing I can think of is that YouTube is not confident in their guidelines & categorization, and does not want to defend these choices publicly.