While Realms devotees love the intricate history of the Realms, most gamers can't even tell the difference between Greyhawk and the Forgotten Realms (
quote from Mike Mearls where he says as much).
I have not met someone yet who is familiar with gaming (note I do not mean 'just entered the hobby') that would not be able to tell the difference between the two. I know the quote from Mike Mearls. I didn't agree with it then, and I don't agree with it now since every gamer I know CAN tell the difference between the two. Mike Mearls job is to make a product and convince people to buy it.
Then there's the question of bringing in the next generation of gamers.
As someone that went from a casual gamer to a hardcore gamer less than 10 years ago, I am not interested in reading fiction or adventures from 20 years ago. So I am not going to be writing Realms material. I'm not alone on that.
Simply you wouldn't have too. You have the main source book. Everything you need is ultimately in there for casual purposes. If you want to write stuff for hardcore gamers THEN you would go to the richer sourcebooks.
That's not to say I'm opposed to research, but if I can choose writing an Eberron adventure or a FR adventure, I'd pick Eberron simply because there is much less material I have to know.
OK so why water the FR down then? If Eberron was there for the people that didn't want to do alot of research, why not leave Forgotten Realms for those people that prefer elaborate stories. Sure the history of those old stories are still there, but the 4e realms is set 100 years in the future to make many of those stories completely irrelevant.
Writing for Forgotten Realms was no more difficult than writing for STAR WARS.
You're free to think what you want, but I don't think laziness had anything to do with it on anyone's side. I'm sure there were thousands of untold stories you can tell about the realms before. But sometimes it's nice to be able to tell the story you want to tell, and not the story you want to tell molded into shape by over 20 years worth of other stories. It's not laziness that drives that, just the desire to tell your story in your own voice.
Then why use the Forgotten Realms? Why not use Eberron, or a homebrew world, or bring back Dark Sun, or Planescape, or even Greyhawk.
I have always been able to add my own voice to the Realms. Never once did I feel constrained (and I have made alot of my own realms stories). People get caught up in the amount of lore without seeing that if you focus on an area, there really may not be that much history. Don't use Shadowdale or Waterdeep. Use Athkatla, Berdusk, or Scornubel. I have developed Scornubel far above what is developed in any of the guides.
the reason I cannot buy this argument is because there are plenty of campaign worlds out there. If one wanted to tell a story in the Forgotten Realms in the first place, why would the lore discourage them? A majour reason for the realms was its rich lore and history. If someone did not want that background why would they want to use the realms?
All that stuff that happened in the realms in the past? Awesome, I can use that if I want to. I can look back on that and enjoy it if I want to. I'm also looking forward to the new stories though. The fresh ideas and original thoughts we'll see going forward.
I am hard pressed to see how a storyteller (DM, Writer, whatever) could not tell an original story with fresh ideas in what was the Forgotten Realms before the change. If you want a new city make it. A new villain; make it. Even Marvel Comics can come up with original storiesthat do not impact their universe on a cosmic level.
Again with calling people lazy... You say laziness, I say too much work for something supposed to be an activity someone does with his free time.
Then that would not be the setting for you. Understandable. I would not call you lazy for not wanting to use the realms. Why would someone want to use the Realms if they did not want to explore the lore?
The Realms that is published now, is completely different from the Realms that stood the test of time. it is a completely different campaign setting.