If that was true then why is there still a good 7 million people playing WoW in the first place?
People may indeed be jumping out but remember that at the end of the day while the game is in decline and that decline is unavoidable, it isn't going to collapse just like that. I agree that as the OP says, wow's age is its ultimate end, and that's because its a prediction I made during the middle of WOTLK which has come true just as I foresaw it.
Me to a friend in 2009: This is the Peak of WoW, there's no way they can possibly do better than this.
Friend: You sure about that?
Me: It has 12.5 million subscribers, it cant possibly get any better than it is, that's the problem.
And I was right...
Cataclysm came, and from there it was a bombshell of down hill decisions to make the game appeal. See, People forget the core reason WOTLK DID so well was BECAUSE it became so casual friendly... for the first time in the game players of every path could get raiding gear, could if they worked hard enough enter the raids that were geared to be more casual friendly. MoP and WOTLK are very alike but id actually argue that some might not know this, but WOTLK was actually EASIER than MoP is now.
WOTLK was so effective because it appealed to so many people, it had an absolute crap tonne of dungeons so much so that leveling was a breeze via LFD and getting to 80 was pretty smooth. The talent tree's made some players near enough godlike in terms of customization so it was so easy to play the game too that at some points people could face roll it.
Then Blizzard made the single most disastrous decision in their development when Cataclysm launched, they basically narrowed the number of dungeons down which meant repeating the same content over and over when using LFD which was a popular tool for casuals to level. That content was ALSO increasingly over-the-top balls crazy about its difficulty curve.
Suddenly even normal mode became hardcore mode for the elite and this was why they had to tone it to hell in 4.2 because it was so stupidly over-the-top that casuals who had just come out of WOTLK with little experience in learning the game and more in enjoying it, suddenly had to become as pro as the hardcore just to play the game.
Hardcores were a flat out minority blizzard wanted to make happy in Cata's launch and it was a BIG mistake to go down that direction. Trying to relive the nostalgia of old dead times is never a good idea if the people that did remember it for all the wrong reasons are reminded of why they hated the game. Top that off with a span of no content what so ever for nearly half-a-year and you can see why Cata suffered so heavily, it just wasn't a good expansion, it totally went 180 on its player base.
But then they did go to far, and even if I am a casual myself and loved LFD, the introduction of LFR essentially was both a great decision and a terrible mistake. Opening that can of worms cannot possibly be closed ever again because now that LFR has essentially become the norm, if they were to close it in WoD they'd be making a fatal decision to go 180 again, and if they do what they did in Cata, that could be the "end" of Wow's subscriber base.
So yes, if anything kills wow its the ranting demand of a small 10% minority that can never be appeased no matter what you give them being given content that wont scratch their taste buds anyway. If anything Blizz should play it safe, continue to appeal to casuals from now on and ONLY casuals and remain true to keeping their interest in keeping the casual player base happy, if they wanted to INCREASE subscribers then going in that direction WOULD be the best call.
TL
R?
WoW's biggest source of income and its biggest number base comes from the lazy ass guy that doesn't like to try to play a game and instead wants to enjoy it with his friends non-competitively.
If Blizzard turns on that community in WoD, disaster is going to happen.