I think part of the troubles with SWOTR is that the initial idea was great. The storytelling that went into the class quest lines, those initial planets, they way it all merged together, was quite excellent.
But then they never really seemed to have an idea of what to do once you finished them. It dripped along with some generic grindy end-game content, that wasn't that satisfying because the story pulled a lot of people in, and end-game repeatable grind just isn't very "story" so it lacks that pull.