In what world are not caring what some fool printed in a book, not caring what other GMs think, and disagreeing with players considered to be anything other than thinking you know better than them?
I call the world Earth.
But if you want to elaborate... okay. Why don't you care what designers may put into their rules?
They are just people: fallible humans. What they write is nice, and I might like some of it. But I feel not even the slightest urge to follow everything they print in a book.
Why don't you care what other GMs think?
Well, in a general sense, I don't care what anyone thinks. It is a generally good way to live life.
Why do you disagree with players?
Well, I disagree with a lot of people. I'm not the type that follows "fads" or "trends" or "what is popular". And I sure don't look at a whole group of people who all think only one thing and have a desire to join them and become "one of them".
Rules for what? How much resources some opponent has? I mean, sure if you run City State of the Invincible Overlord, pretty much every building is keyed in the whole (large) city. You still can't tell who will work for whom, exactly what their goals and resources are, etc. Plus you will have to play in something with this kind of level of prep.
Well, that or you have a VERY slow moving kind of plodding game where much of the time the players are simply 'fiddling around' or doing something of little consequence. It would be effectively impossible to sustain a game at any great pace where you had to make up all the financial and social details of the life of tons of NPCs and figure out how the entire world works in detail.
I mean, we decide to break into a warehouse in Fong Town. Who does it belong to? What's in there? Can they afford magical protection? Do they have influence with the town government to get the PCs in trouble? I believe you can sometimes construct this amount of detail in a very restricted sense, but that means you better have the PCs on a short leash so they don't go outside that!
I ran this kind of campaign, it definitely wasn't sustainable at the pace we moved at! In fact it devolved down into essentially narrativist play after a few months. Not that I'd really heard about those techniques (it was the '90s) but focusing on the plot as being the thing that was the game part of play got pretty interesting. Not that it was easy to do with 2e, but kind of possible.
The above is very possible, as I do it. And so do a lot of other DMs.
One type of DM won't, or can't put much effort into the game beyond just playing it. Much like say a board game. This type of DM, the player DM, wants to be just like the typical player. And that is putting very little effort, often none, into the game. Even more so outside of the game play. The casual player and player-DM just wants to show up, play the game for a couple hours and have a fun time. This DM does not make up much.
The other type of DM puts a lot of effort into the game. Often many, many, many hours per week every week. Nothing like any other type of game. This type of DM is far beyond and apart of the typical player. While the typical player just makes a character and shows up to the game ready to play, this DM does tons and tons of work outside the game. This DM makes up tons and tons and tons of content.
And the big difference too is one DM does nothing and the other writes an adventure.