I had a thought last night, that at first was strange, then started making a lot of sense.
What if Blizzard's long-term goal is to get a stable core of around 2-3 million subscribers?
Considering the current number is 7.6m, and has been as high as 12m, this might sound like a dumb idea, but I think this is what they are going for. Here is why I think this:
Mists of Pandaria was significantly less casual and alt-friendly than Wrath or Cata. A lot of the easy-mode gameplay, leveling, and catchup mechanisms that were there in Wrath and Cata were not there in MoP. On top of that, you were rewarded for taking the time to get your legendary, whereas if you did not put the time and effort in to get your legendary, raiding at the top of the end-game in the final patch was difficult, or impossible to find a raid if you were a pure dps.
This, on top of the first expansion since vanilla where you were not eligible to fly on any alt until level cap.
Over and over, we see elitists complain about casuals/carebears. We see the casual/elitist argument brought up again with flying in WoD. Then we see - the lead systems designer, Ghostcrawler, comes down on the side of the elitist - not the casual.
Despite having been an elite player doing high-level progression raids at different times of my wow career, I've always been staunchly in favor of casual policies. So I was very unhappy with the insane rep grinds and removal of tabards. I was unhappy with the removal of the Dalaran portals. I was unhappy with no flying - even on my first toon - through pandaria leveling. And I felt it was even worse not flying on my 10 other alts as I level through Pandaria.
But the Blizzard designers decided this is how they want their game. Less casual friendly. More in-line with the hardcore elites.
Then I started thinking about the psuedo-server merges. How multiple realms are being connected together - not just to fix population issues now, but for the future.
And then I realized - holy heck, this all goes together.
The way I see it, the lack of flying, another long mandatory legendary quest, no reputation tabards, hard elites that require travel time, requiring flight point usage - this is going to drive away the more casual customer.
Those of you who are self-described elitists are going to love it. But it will drop subs, significantly, as more people who are strapped for time are just not able to be competitive, or to accomplish much in the new hard(er)core model.
And then I thought - what if this business model actually is the long-term plan for success? I think an MMO, even of wow's size, could scale down their servers, their developers, their GM's, and make themselves more streamlined for the next 20 years, even with a sub loss of another 50%+.
And then I thought... man, that could be really, really smart. It will make me personally sad, and others personally sad, because of the large amount of us who prefer more casual-friendly gameplay. But from a purely business sense, as well as an artistic sense, in terms of "making the game we really want to make," this could be a really sustainable model going forward, with the idea that the more hardcore/elitist player will be more loyal to the game than a casual player, therefore smoothing out their overall subscription numbers.
I would guess that to make up the lost revenue, Blizzard will be attempting to shift demand for the more casual player to their other IPs - Hearthstone, HotS, Titan. Since Titan is expected to be F2P, we could be seeing a setup where blizzard is purposefully pushing away it's more casual WoW customers and into Titan.
Here's a tl;dr: Blizz hard(er)core game design will reduce population to a sustainable 2-3m more hardcore players, and this is their long-term goal.