Games Workshop was churning out a lot back in the day too, but I think it has as much to do with the economy as anything nowadays. I remember when there was a Games Workshop official store in a lot of major cities... but I digress.
I was thinking of roleplaying games, but looking back, I DID say "tabletop games", which of course includes RPGs and miniature wargames (and more stuff too). But GW works well in the conversation also! I would say that GW's current output, as far as multiple game lines, was greater in the past, but it feels to me that they are putting out more product for their main games, the Warhammers! And, they are starting to bring back some of their "specialist" games on a limited basis (BLOODBOWL!!!). The number of GW retail stores seems to wax and wane, but they are still opening new stores, we just got one in my area, Boise, Idaho!
Bottom line with GW, IMO, is that they do have a relatively tight focus on Warhammer (fantasy & 40K), and a somewhat smaller focus on their Lord of the Rings game.
I said they killed them off, I stand by that. They had to kill them off to funnel down to one setting which they could focus on.
Well yeah, I think we are in agreement there. We might disagree on WHY they "killed off" settings other than the Realms. IMO, they didn't stop non-Realms support to focus on licensed "transmedia" opportunities (film, video games, novels, etc), but rather to simply focus on the game itself.
I'm not asking for much at this point, just would be nice to add in stuff about Dark Sun, Greyhawk, Mystara and Dragonlance.
To be fair to WotC, and as I'm sure you know, in the 3 core books they have a very even mix of references for the many classic settings. Of course, the Realms gets a bit more support with pantheon and human ethnicities, but still overall very even. Even in Volo's Guide there are plenty of non-Realms references, despite the book being "set" in the Realms with Volo and Elminster.
The only strong support the Realms get in 5E is in the adventure paths and SCAG (Sword Coast Adventurer's Guide). Which is significant, surely. But each adventure path was also EASY to adapt to any other similar "standard" D&D fantasy setting like Mystara, Greyhawk, or Dragonlance, or your homebrew. And SCAG had a nice appendix adapting the character options to the other classic settings.
If WotC feels they must focus on one setting, choosing the most popular setting is the only logical choice. However, we get the best of both worlds with the references and conversion guidelines for other classic settings. The knee-jerk reaction of some fans, "What?!?! The Realms AGAIN!?!?!" is getting beyond tiresome to me and I would just ask those folks to realize, it isn't about you. It's about what's best for the community and the game at large. Grow up, basically.
I would be ecstatic if WotC decided to publish some Mystara focused products . . . or really, products focused on ANY classic setting other than the Realms. I love the Realms, but I also love all of the other classic settings equally as much, with Mystara being my fave of the faves. But I realize that WotC can't cater to my special snowflake needs and has to look at the health of the game overall, and splitting the focus between multiple settings is, well, unwise.
What I really want WotC to do is to open up the DM's Guild to all classic settings and products. Give the fans the opportunity to design and share the kind of products they want that WotC can't afford to do themselves. And with the DM's Guild just going POD (Print-on-Demand), you could even potentially get those products in physical form for your bookshelf!
EDIT: Cleaned up some stray sentence fragments.