I consider my role to be a cop, not a lawgiver. Describing forum ethics is not a part of my job. We already have tools to enforce the things you said: if someone writes stupid comments, spoilers, or trolling comments, anyone can downvote them. My superpowers will be needed if someone starts abusing these tools, e.g. by mass downvoting, because that's what other users cannot investigate.
What I said is orthogonal to whether having explicit debate about forum ethics is good or bad. I can imagine it going either way. I think most people would agree with the examples you gave here. Anyone should feel equally free to initate this kind of debate, and my opinion should have no special weight there. Opinions of people from MIRI or CFAR should have extra weight, I think, but I am not in that set.
I consider my role to be a cop, not a lawgiver.
Right, As long as you know what laws to enforce.
Some time back, I wrote that I was unwilling to continue with investigations into mass downvoting, and asked people for suggestions on how to deal with them from now on. The top-voted proposal in that thread suggested making Viliam_Bur into a moderator, and Viliam gracefully accepted the nomination. So I have given him moderator privileges and also put him in contact with jackk, who provided me with the information necessary to deal with the previous cases. Future requests about mass downvote investigations should be directed to Viliam.
Thanks a lot for agreeing to take up this responsibility, Viliam! It's not an easy one, but I'm very grateful that you're willing to do it. Please post a comment here so that we can reward you with some extra upvotes. :)