But I think @
billd91 brings up some good points, that there are different cohorts, different generations in which a group came into the game. So we can look at the largest cohort as being those that started in the late 70s to mid-80s, the "D&D Boomers." Presumably there was another cohort in the 90s, but I think it was significantly smaller (plus that's when White Wolf was really popular, so a lot of gamers were going in that direction).
Indeed. I'd describe the 90s cohort as "White Wolfers". TSR was churning out shovelware at about 5 books per month, but most of the
new players in the 90s were playing the younger, cooler game in preference to D&D. (The really huge cohort was the early 80s, of course, with the Satanic Panic - and selling 750,000 copies of the rules per year).
Then we have another cohort with 3E and seemingly one with 4E as well.
We have a large cohort with 3.0 that also includes the d20 glut. For a brief while, thanks to a complete game revamp and the OGL we had a draw of cool as well as an onramp. D&D managed to present itself as cool briefly to the sort of crowd who was finding the FSF cool - and d20 is a whole lot less arcane than D&D (and looks a lot less arcane than it is). It fell away as all such gluts do. There was, so far as I can remember
very little such effect for 3.5 - it was the edition no one wanted or asked for and came out to general grumbling - but very decent profits as most people switched.
And then with 3.5, with WoW, and with the end of the d20 glut things fell away. A lot.
4e was meant to reverse the trend. There are
lots of reasons WotC messed it up including a murder/suicide derailing DDI - but it didn't grow the base. Pathfinder has
muchbetter surrounding values even if I don't care for the game but they're barely in a position to grow the base either. The hooks for starting up just aren't there other than knowing people in the community.
Recent interviews with Ryan Dancey and Montecook help put this in perspective. Mearls in an interview as early as 2010 admitted they drove away their players although they did not mean to. In 2012 when Monte was asked to come work for WoTC again the words "save D&D" again were used. Dancey in his interview estimated D&D was 1/3rd the size it was in 2000.
4E would have brought in some new players but they drove off over half of the existing player base and more like 2/3rds it seems. If 4E brought in a larger % of newer players that 2/3rd part is an even larger%. Even Jonathan Tweet has out right said 4E was rejected by the D&D player base.
Ryan Dancey
http://www.enworld.org/forum/showthread.php?360842-License-to-Game-An-Hour-With-Ryan-Dancey!-Acquiring-TSR!-The-OGL!-Releasing-D-amp-D-3E!-Saving-D-amp-D!-Indie-games!-MMOs!-Pathfinder-Online!
Mike Mearls
http://www.escapistmagazine.com/articles/view/video-games/issues/issue_271/8109-Red-Box-Renaissance
Tweet
http://frabjousdave.com/creative-colleagues-jonathan-tweet/
Monte Cook
https://www.youtube.com/watch?v=hBmzrQnxf4w
So other than Mearls (and much has been written about his relationship with 4E) you're citing two designers of 3.0 and the designer of the OGL.
Thing is all three of them are right. 3.0 was a major high point - and there's been attrition ever since. How much has anyone seen 5e outside the bounds of the FLGS?
Yeah, I think it is pretty clear from insiders that 4E did poorly in terms of acquiring new players and keeping existing ones. Tthis goes against the view that I've seen floated that 4E only "failed" in that it didn't reach company expectations. But I think it goes much deeper than that, especially given what Mearls, Tweet, and Dancey said. Dancey tends to have a pretty good read on such things and even if he's off by a significant margin--say half rather than one-third--that still means that D&D now has half the players that it did in 2000. That's not simply a matter of not reaching expectations, but actually flopping.
If D&D has half the players it did in 2000 then by my reckoning that means 4e was pretty successful. I've presented Google Trends before on the subject - but between January 2004 and December 2007
D&D lost over half its google searches. This is what I mean by 3.5 haemoherraging people. Even if D&D has only a third of the people it had in 2000 that wouldn't surprise me - and most of the loss was under late 3.0 and 3.5.
Did 4e ever reach the heights of 3.0? Nope. All it did was almost held steady. Which is a pretty huge thing when you compare it to what came before.
Now part of that is Pathfinder, so if we use a broader definition of D&D then perhaps the overall fan base hasn't shrunk. I honestly have no idea. But I think it is safe to say that people who play D&D (logo) are fewer than they were a decade+ ago.
Even counting PF I think the overall fanbase has shrunk quite a lot. The high point was in the 80s when they were selling 750,000 copies
per year. I'd be surprised if 3.0, 3.5, or even 4E+PF sold that
in total.