Urriak Uruk
Gaming is fun, and fun is for everyone
The FR being the most popular pre-dates 5E, that was why they made the decision. Ed Greenwood's relentless support of the Setting for several decades is probably to blame: most other Setting creators moved on.
Fair. But the 5e content focus on FR isn't exactly diverging people to other setting either.
This attitude infuriates me. The type of casual fan you describe infuriates me. It reminds me of somebody describing the virtues of Budweiser while repeatedly refusing offers to go get a beer that is of even slightly better quality. That guy would probably like Granville Island if he knew what it was, but he's refusing to find out. Likewise, these "casuals" lack of interest for new horizons makes the game stale and bland. Like Budweiser. Stop drinking garbage macrobrews.
To change tracks for a few moments, Eberron: Rising from the Last War, the third setting guide for 5e (or fourth, depending on how you want to view the Wayfinder's Guide, which is a total fracas in and of itself and my heart goes out to Keith Baker for making it in the first place despite the controversy it would inevitably cause), just officially released today, and I am loving it. There's a lot of detailed material, both fluff and mechanics, that it offers for my use, and the Gazetteer of Khorvaire, detailing all the major nations of the continent is nothing to scoff at either. And yet, there's a twinge of pain, as I know that future support for Eberron from WotC is unlikely; there won't be any books detailing Xen'drik and Sarlona, and even the Khorvaire Gazetteer misses a few things, and the book yet again zeroes in on Sharn, City of Towers that is in need of exploring for the 13th time apparently. Baker's releasing Exploring Eberron in December, which will fill in some of the unexplored corners of the setting, which is awesome. And Eberron has the advantage of a lack of an advancing metaplot, which means all the sources from 3.5e and 4e are still relevant, just in need of a mechanics conversion.
Not so for Forgotten Realms, at least on the second point; on the first, I'm not sure where to look for community engagement. There's this Crown of Eaerlann thing coming out some time soon, which is... something? Anyways, there is even less support for players and DMs wanting to go beyond the Sword Coast, Mulmaster, the Heartlands, and Chult in 5e, and trawling through the wikia and through old books isn't even taht helpful as all the information in there is in-setting outdated by 13 to 135 years and two cataclysms that rewrote the face of the continent. I want to run a game in Thesk. Maybe go east into Yaïmunnahar, or even further and into Tabot. Ok, where do I even start? And I can't just go and open the equivalent of "Secrets of Sarlona" for Forgotten Realms because all the info in there is outdated in-setting!
I mean, for goodness sakes, no setting (FR ironically excepted) is going to get much material beyond it's core area, which with D&D's largely Anglo-American origins are all very European inspired.
FR has the Sword Coast, Greyhawk has the Flaeness, Eberron has Khorvaire. Sure I want more material for the other areas, but I also understand that books can also be so long, and a few pages more for Xen'drik means a few less pages for Khorvaire. And most people do play in the "core area," so it makes sense they get the most material.
What frustrates me here is that FR has by far the most material in 5e. It's almost certainly going to get more material too. Now considering we are likely only going to get only one setting book per year, can we instead get ones for actually different worlds?
I mean, if some of the rumors are true, you're likely going to see upcoming adventures cover places like Lantan and some-far off area like Kara-tur or Al-Qadim. Isn't that better, to get a full Adventure book that actually covers an area deeply, instead of getting another setting book that will cover the non-core area with a handful of pages?
Tomb of Annihilation is an AMAZING guide to Chult, and from what I've heard Out of the Abyss is a good guide to the Underdark. Don't you prefer more books like that, instead of a Rising from the Last War, which you mostly already have?