As a counterpoint - initially, I loved 3E's more simulative focus (as compared to 2E), and I dove into making sure that everything would 'interact with the world' in a plausible way. Then I realized that it added absolutely nothing to my games, and the players didn't notice that I had given the BBEG ranks in Knowledge (Religion) or that the too-big-for-its-farmland community was exactly as big as it could be with the conveniently-located 9th-level druid supporting their crops or whatever.
Statblocks with pure combat stuff are just fine by me. I wouldn't mind a 'rituals' section afterwards, but I can live without it.
It's not about simulating, it's about ease of play.
One of 4e's stated purposes is to speed up play. I fully agree that not every demon needs to be able to teleport, and that streamlining monsters is a good goal to help achieve that.
However, more so than running combats, what slows down my games is when I hit a "mental speedbump," when I have to stop and think about what adventure is going to take place next and how to give it linking traction with the current group's activities. It's a bigger risk for me as an improvosational DM, but even well-prepared DMs suffer it when the PC's go in a direction you didn't expect or prepare for.
These are the infamous "let's take 5 or 10 while I pull something out of my behindus" moments that grind the game to a halt.
These moments are avoided by monsters who are part and parcel of the world they occupy. Because it gives me linked inspirational juju: I can look at the terrain they're inhabiting, look at the monsters listed in that terrain, see what they're associated with, figure out how that works in the world....
Say I have a BBEG who, for some reason, has ranks in Religion. I want the group to fight him. They're in a tavern. How do I get them from point A to point B? How do I give them the dozen or so encounters they need to gain a level when they kill the BBEG (no better feeling in the world!)? Well, let's see, his ranks in Religion means he might be associated with some clerics of Evilgod. It means that servants of Evilgod would help him out. I can grab some Demons and Devils...this means that we can have a summoner. Summoners are arcane spellcasters, arcane spellcasters need a school, we're in a big city, this city has a magical academy, academeys are schools, schools have students, students like drinking BAM.
Now, I have a way for them to get from Point A to Point B. They meet a drunk arcanist who lures them (somehow) back to the magical college, where they uncover a demon-summoner who is sending his underlings to go work for the church of Evilgod, where the clerics are actually on the payroll of the BBEG.
I can probably milk 13 encounters out of that.
All because of inspiration on the fly by an offhand skill.
The same is true of the druid who helps the fields.
I don't look just look to D&D to fill roles in my pre-imagined adventure. I look for D&D to give me the adventure on a silver platter, just waiting for me and my friends to connect the dots.
4e doesn't look like it will have as many dots to connect.
This will make me spend more time developing adventures, leading D&D to become a bigger time sink for me.
This is bad.