I can imagine that some of you at this point are already thinking, that maybe WotC doesn't really use any "rules" because building encounters and creating monsters "are an art, not a science". Well then, why doesn't WotC very honestly say so in the DMG? If the book's purpose is to teach people how to be an effective DM, and the truth is that you can't define "rules" for certain stuff, then it would be a good idea to teach that as well.
Edit: for whatever reason, the original quotation to which I responded is not showing. It was from the OP: "I can imagine that some of you at this point are already thinking, that maybe WotC doesn't really use any "rules" because building encounters and creating monsters "are an art, not a science". Well then, why doesn't WotC very honestly say so in the DMG? If the book's purpose is to teach people how to be an effective DM, and the truth is that you can't define "rules" for certain stuff, then it would be a good idea to teach that as well."
WotC does very honestly say in the DMG and elsewhere that, ultimately, it is up to the individual Dungeon Master to decide how to use any and all materials. The reality is that almost any experienced DM knows that any "rules" for encounter building are guidelines at best, and the DMG is very clear that these are suggestions. That said, its target audience is clearly new DMs, and so it provides some very explicit guidelines for creating combat encounters of varying difficulties.
I'm not sure what you are expecting. The tone of your post seems like you are looking for a "gotcha" - that if WotC's own adventure designers, all very experienced DMs aren't sticking to the letter of the guidelines provided for new DMs, then they are being dishonest about their product. But no such thing has been promised. And, given the inherent complexity of encounter design, given that every single party and collection of players is unique, expecting a single set of guidelines to act as firm "rules" for every possibility is silly.
I don't know whether or not their own designers stick to the letter of the DMG guidelines. I also don't care. I care if they are designing good encounters that work in the context of the adventures they are writing, with the full expectation that I am going to tweak things for the needs of my particular group.
Your post reads like "if a beginners guide to playing piano isn't clear that it won't turn you into Mozart, then it is LYING." Rather than being, you know, a useful place to start.
