This is part of a trend of just putting way, way too much fluff into the core game. They seem to feel the need to explain every little thing -- and to do it in a way that implies it is so across all D&D settings. I just want a toolbox of monsters, spells, etc. to throw into a home brew fantasy setting. I don't want a Weave, a Far Realm, wild mages, Blood War, Great Wheel, et al. in my game. I've never minded that those toys were in the box. I've just never used them, but good for those who did. If I wanted a setting that was tightly integrated into the rules, I'd play one of the other games that offered something like that.
Probably part of it is that, while the current team is fantastic about building mechanics, I haven't been particularly thrilled with the fluff they've added. That's a taste thing, and I might feel different if I was bowled over by the specific fluff.
