Assuming that the OP isn't trolling the waters, I'll bite.
MMOs are quite social. The issue is that it isn't the -same- type of social behavior that existed during the "old days." This is largely due to things like Facebook, Smartphones, voicechat, and social media in general. Back in "the day" it was primarily AOL chatrooms, AIM/other messangers, and EQ. Bulletin boards and forums weren't new but weren't super widely used, and voice chat was non-existent. Social media largely meant your forum/board presence as opposed to your tweets/fbupdates/et al.
To add what early players believe the word "social" means back into mmos, you have to regress progress in several technological areas to achieve similar results. Not to mention narrowing the mmo market down to just a couple of quality titles that actually work occasionally.
As has been stated before by others, including myself, the people that tend to crave forced socialization are people that are not naturally social themselves. I haven't really experienced this lack of socializing that others have, because I tend to talk a lot in chat/voice while playing games, regardless of the group paradigm. People who are not normally social, unless forced, will not socialize in most mmos. Which is why you end up with all the silent Sallies and shit when you do dungeon finder groups. They just want to finish and gain rewards; they do not want to socialize. This is little different from the quiet players in EQ that only occasionally responded to people. The difference being that instead of being forced to socialize to progress (largely endgame+) they have the option to play however they want.
Honestly, to "re-socialize" mmos, you should just add a box to dungeon finders et al. This box tells people you are in it just for loot (speed run box or something) and not up for conversation. This way, people who don't have the box checked, will find people who want to chat occasionally in the random dungeons more than they will just get groups full of anti-social people or people who don't want to talk. You can't restrict people as much in this market as you could in the good old days. You gotta have options.
