Group play and community is a balance issue more than anything else.

Opinion on Grouping as an Element of Community Building:
I believe that the solo grind should be somewhat of a drag and that the group grind should be far more efficient and happiness inducing.

Observation:
Unfortunately, the gates have been opened up and the time investment that is considered reasonable for certain activities in games has changed. Mini games on smart phones and pad devices with low personal investment and a high level of engagement now exist. I think this mindset has modified the more traditional idea of a communal game and it shows.

Opinion on Community Building:
It is important and the focus should be on the mechanism for the creation of community. The trick is to make group game play more "interesting" or "reasonably more advantageous" for those competitive animals. It is the structured interaction that is "evolved" in each generation of "group play mechanics" sprinkled with "revolutionary" elements in new MMORPGs that is important.

The shortest and easiest answers are usually the best. Hence i can put the answer to what all MMORPG's need to succeed into one single word:

Catgirls

And that is all.

I disagree with this article on a lot of points. First off, I think that any destructive effect that the Looking for Dungeon tool had on World of Warcraft wasn't that it it destroyed 'communities' on a server, but instead intensified the necessity of cutting through content quickly (and the ability to go through the leveling/gearing up in radically different ways) which the game designers weren't able to keep up with.

The disparity of methods to reach 'endgame' content has allowed for a wide berth of different sub-communities to exist in WoW, as players wind up being isolated from others who are interested in different aspects in the game... and they love to bicker between themselves. To say that the community has gone bad or is nonexistant isn't really right, it's still there, but it allowed itself to be specialized in so many angles of the game that you have to look around to find that sweet spot of a guild or server that has an attitude that you like. You can head to Proudmoore-US, for example, if you'd like to hang out on a server that has low tolerance of hatespeech in trade chat. You can head to Wyrmrest Accord if you're a lore nut. You can pack off to Ysera or Sen'jin if you're looking for an intense Raiding community. And you'll probably find guilds on some of the servers that are interested in participating in all aspects of the game.

WoW aside... I also take issue to think that FF14's problems were due to them trying to bring in a core of solo'ers. The inefficient leveling and quest system, horrible interface and server issues thanks to Japan's earthquake and tsunami back in March are to blame for the problems FF14's 'community' problems.... because the people who probably would like to sit down and participate within the communities within the game weren't just able to tolerate such a poorly-delivered product.

However, to expect a good community to spontaneously appear days in response to what you described in FF11 -- that I'd like to call the "tribe is required" phenomenon (which I have personally encountered when I started playing MMOs back in 2003 with Ragnarok Online) -- just is no longer a financially safe design tactic for game companies these days. The consumer base for MMOs have expanded beyond those who were okay with spending weeks making items with much intense involvement in finding specialized crafters with rare recipes, or spending months getting to max level by grinding elites with a party of five that you spent hours trying to assemble. Granted, you are likely to get a community out of small specialized games that have that kind of environment, but game developers need to eat; or worse, they need to appease a corporate parent company with stock holders. They have to invest in a game design that won't cause potentially hundreds of thousands of people away because they don't want to kill Pecos for 15 levels for a week's worth of effort.

The most important thing that a game designer can do to help build a community is to not make a terrible game. If the game is good, people will come and participate with other players. There will ALWAYS be that kind of casual that you dread -- the player who doesn't want to get in a guild or chat on forums or take part in player-started social events -- because you can't force people who don't want to interact with others into interacting with others without there being a nasty side effect on those who just simply want to have the ability to do something on their own without it being a giant federal emergency.