For some, when it comes to game mechanics, less is more. For example, when looking at 3rd edition, on one hand, one of the things many people say it did right, was make things more universal. While there are benefits to having one method of creating an NPC that will match up with a player, and of having standards for lowering and raising monsters, either based on hit dice or giving then levels, the problem almost becomes that you are no longer player Dungeons and Dragons.
Because you know what other systems use such a methodology? GURPS, Hero, Mutants and Masterminds, and I'm sure many others. But in Dungeons and Dragons 3rd edition, the player creation aspect is so highly specialized and customized that for the Game Master, to honestly use it all the time, can be nightmarish. This isn't to say that many Dungeon Master's don't love to tweak or design or create. In some venues, this is WHY they are Dungeon Master's. In other's, because they are Dungeon's Masters and not playing, they get to tweak that part of the game like a player gets to do so with their character.
Each player though, generally only controls one character. If a Dungeon Master is making highly unique and customized characters and monsters each game, even if his enjoyment is high, his prep time is going to be huge. And taking up large chunks of prep time is never seen as a good thing.
So 4th edition went back to the drawing board on the monster side, and in terms of how monsters work, I think they largely succeeded. Oh, they screwed up the damage dealt and hit points possessed, but those aspects are able to be tweaked fairly right away. The presentation, the building, the roles, these things are shorter and sweater.
Yet in terms of Monster Manuals, after the third one, WoTC went back to the drawing board to tweak monsters because of the tweaks they did to the players in the relaunch of the Essentials line. It was another case of, "We're not going to reprint the core book because that's unnecessary, but here, have a book that fills the exact same role, including takes on all the old stuff, but is not actually a reprint." They followed up that Monster Vault boxed set with another monster product that failed to go epic but was well received due to the amount of information each monster had. It was almost like world building through the monsters. Very well done and very well received.
In terms of making monsters more, Open Design has their own Ecologies compiled from Kobold Quarterly. Paizo, while publishing Dragons and Dungeons, printed a compendium of Ecologies. Currently Paizo has a line of products that revisits monsters and expands them. The focus isn't on the game mechanics, its on making the monsters more useful to the Game Master by expanding information on where they live, how they live, why they act the way they do.
This was a fairly regular feature back in the day for Dragon magazine. Wulfgang's Ecology of the Ghoul is still one of my favorites from 2nd edition.
4th edition may have had some, but I honestly cannot recall Dragon online having any great impact on how I look at monsters. It's focus has been weak. There was a brief time when they created a new feature called Creature Incarnations. It featured a variety of monsters pulled from one monster. You can see one free article of it here. Its not bad in my opinion but...
I've mentioned before that Dragon Magazine used to be a fantastic resource for Dungeon Masters and players and I feel its become a little more than a preview and feedback machine. Back in 'my day' we had The Dragon's Beastiary and Ecology articles. When Dragon was feeling real generous and wanted to make the reader feel he got a huge bonus, we'd get a Creature Catalog, almost like a miniature sized Monster Manual.
If Dragon continued to support and publish the Incarnation articles, that would be one thing. You could say that they went in that direction. In the years, and its got to be going on something like four years, so over forty eight issues, there are less than twenty articles that fall in the heading according to a search on the article compendium.
When other companies are publishing books, in what is supposed to be a depressed buying market, especially for what are niche products, products that focus on the background and organization, and methodology, not on new game stats, if Wizards of the Coast is serious about learning from its past efforts, this is one of the directions they need to embrace.
The Grandmasters -
1 hour ago