What Went Wrong With Star Wars: The Old Republic?

Gamasutra is offering a feature on the mistakes made by the Star Wars: The Old Republic developers that led to its less-than-satisfying performance with subscribers. They identify "lack of social interaction" and "ineffective monetization design" as the two culprits, so here's a snippet on the first:
Lack of social interaction

What separates massively multiplayer online games from other simpler products is the promise of social interaction. A much more consistent play experience can be had with a single player or small team competition game for those that are not seeking this social interaction from their play time. It is thus imperative that an MMO be built to provide maximum positive social interaction. Most social interaction takes one of three forms, in addition to chat functionality:

A. Cooperative Play: Taking on an opponent with five, 20, or even 100 of your friends and teammates adds a great deal to the excitement level of a game. Not only does the result of an encounter require a lot more communication and team work, it also adds additional randomness that can make every encounter unique. Doing well in such situations also can bring great prestige as others will come to admire you if you perform well under pressure when they are depending on you.

The best parts of SWTOR are the story line missions. Their cinematic quality makes you feel like you are in a movie that you control. The weakness of this design is that the focus is on a single player, and that a full group could be just two players and AI companions. This gives SW:TOR the feeling of a "Massively Single Player Game". While there are missions that can accommodate more players, the game never manages to escape this feel.