They should have kept developing the "fourth pillar"

90% of the WoW Kiddie players you mean, ie the players that think the game begins at max level, when raiding like it's a job for phat lewtz is all you do. The players that blaze to 50 as fast as they can, then complain that there is no endgame content. The players that, once they get a new Op or Flashpoint, conquer it on Nightmare inside of 4 days, then ask for more.

"Mutiplayer" is the second M in the genre's name. Seems pretty black and white to me.

And that story can be consumed in a matter of days or weeks. When your business model depends on monthly subscriptions... there might be a problem there.

WRONG! I mean you can solo everything.. Even the big gorilla WoW you could play entirely alone *sigh*
I agree with OP and other people that the focus should be on the story and not in running after the boring lvl 50 end contcent...

Most of the modern MMO is like this, if it's too group relied it will becomse niche game. Even the vanilla WOW, sure you would miss a lot of fun but it's totally possible to solo to 60.

World of Warcraf can not only be soloed from 1-90, but you can do so without ever even engaging in combat. There was a big piece about this in Massively shortly after MOP came out.

Some tauren player leveled all the way to max level doing nothing but professions and exploration. Your argument is invalid.

The development strategy of concentrating on story failed.
The development strategy of being able to solo everything has failed in every MMO except WoW.

The game focused on bringing story to the player.

It obviously did not worked that well on the long run.,,,

but story kept people playing when the story stopped people quit grouping and endgame has not kept people playing

The development strategy of focusing only on story did not fail. It failed because they did what WAR did and tried to have something for everyone, even though the game was clearly advertised to cater one specific playstyle.

For example, WAR was advertised as an RvR game. This would be the MMO for the PvP playerbase. However, what was launched was a mess of boring and dull PvE content, extremely easy leveling, no endgame and some RvR tacked on. Mythic later acknowledged that they should have stuck to their original guns and made it an RvR game, period. When they went the WoW route, the game failed.

Same thing happened with SWTOR. The game was advertised as a story driven MMO. What we got instead was a really cool leveling experience and a story that ended at max level, then the standard MMO crap that few enjoy. Had the developers just made this game about the story, it would have catered to the people that came here - they would know exactly who their audience was and what they wanted. Instead they try to be everything to everyone.

And that never works.