It ain't fluff. It's useful game mechanical information. A blue dragon using Mirage Arcana isn't superfluous description, it's an essential part of using that monster in the game.
Sure it is, and if the creature has the ability, it's listed. 4E blue dragons aren't illusionists, and don't have
Mirage Arcana. If they did, it would be listed, with a description of the ability, which then gives you ideas on what it's capable of. Admittedly, 4E has few out-of-combat abilities listed on monsters, seemingly by design ideals.
OH BOY MORE PREP WORK! Thanks, Paperwork Fairy!
You seem to be missing the point of what I want out of an MM: stuff I can use to play the game. Not prep. Play.
Dragons serve two basic purposes. They can either be a dangerous encounter that the PCs come across, or they're the BBEG. Everything you need for the dragon to be a dangerous encounter is right there on the page. The issue is that you want your spell-casting scheming blue dragon. Unfortunately, you're playing the edition where blue dragons are aggressive forces of elemental lightning. The basic 4E blue dragon doesn't have the scheming illusionist side, where it waylays and wears down its opponents. It's an aggressive predator that swoops down out of the sky and pummels the party like the sudden storm it personifies. Everything is there, even in the terse 4E micro-fluff. It says where they're commonly found, how they usually approach getting into combat, it gives you a stat block so you can see how intelligent they are and emphasizes particular skills. It gives sample encounters with peons. The only thing it doesn't do is draw a lair, which you may not even use if it's an encounter outside.
If you want something more out of your dragon, you're going to have to do some prep. It's not like it has to be a lot of work. It certainly can be if you really want to detail and flesh things out. If you seriously don't want to do any prep work whatsoever, it really sounds like you need either pre-written modules, or books detailing things lairs and abilities like the Dragon manuals, both of which the publisher provides.
When I don't want to do prep, a toolbox is useless to me when what I need is a chair, RIGHT NOW, because I'm sitting in front of my players and they are looking at me expectantly and hoping for an exciting adventure.
Toolbox is all well and good -- it's perfect DMG and online supplement material. It should absolutely be there. But the game also needs to present me with prefab stuff, and it needs to do this right out the gate, in the core books, because if I'm a newbie DM and I want to run a game tonight, I need to be able to.
I should be able to pick up the game (the three core rulebooks) and play the thing that very night if I want to, just by following the instructions on the page.
Which you totally can do. Everything is right there. Is it going to be some epic Tolkienesque adventure full of subtle plots and nation-changing scope? Not likely, because no time has been put into developing such an extensive massive plot. Can't think of what monsters to use or a quick plot idea? The DMG provides a sample adventure for you and your buds to jump right into.
But everything requires some prep time to some degree. As a player, you have to make your character. You can't just roll randomly, you have to sit down and put it together, generate your stats, pick your race/class, pick your powers and feats. As a DM, you either arrive on game night with some sort of idea of how you want things to go, such as you reading up on the Blue Dragon, and seeing how it uses its illusionist abilities, so you're already planning on how to wear down your PCs before the dragon finally comes out to fight. Or you arrive with absolutely no plan, which means you're doing your prep on the fly, because you're having to determine what the PCs are facing as things go, then read up on them, then read up on their abilities and minions and traps, and if using miniatures, setting up the map.
And, I think it's worth mentioning again, this isn't about "fluff vs. crunch." What I miss about dragons in 4e isn't fluff. It's all useful game information, it's just not combat information (4e provides me, well, TOO much info on that front). Since the game is more than combat, I don't think it's asking too much for WotC to provide DMs with more than combat things to do.
But for all intents and purposes, that's what a MM entry is for. That's why the stat block gives defenses and hit points and combat damage, because its meant to be used for when the PCs get into a fight with one. Could the entry provide some more info on say personality and motivations? Certainly. But in the end it comes down to the context, which is where a DM comes in and decides just what the situation is and how this particular creature will react. And likely there were plans on producing the Draconomicons from the get-go, where they knew they were going to provide a lot more detailed information on their iconic dragons.
Those NPCs are going to deal with various creatures throughout the realm. I want someone else to do the leg-work for me on those parts. I don't really want to design every aspect of the Gnolls that worship the Demon, I want to spend my time working on the Demon itself and therefore giving my players interesting interactions that they choose.
But aren't the characters going to be meeting up with these worshipping gnolls a fair bit, probably more than the demon itself? If not, then it doesn't matter if they have no details. If so, then you would develop aspects of the cultists, since you're wanting to make it interesting for the PCs when they come across them.
I'm not sure what you expect the MM to give you. They present the 'basic' creature. If they're being used for a specific purpose in your campaign that's more specialized, well, the publishers can't anticipate your needs and develop them fully for you. And if they do, then such specialization can then make the creatures harder to use in other ways than the 'generic' version.
I can get much more out of my games spending the lion's share of my time designing patrons and villians and other NPCs rather than designing goblin bands, orcish hordes, or gnoll cults.
Again, it depends on your focus. If you feel that the these goblin bands or gnoll cults aren't worth the time to invest in developing, what does it matter if you're using a generic stat block? Why is the town smithy more worthy of being fully developed than the gnoll high priest?
