It doesn't help that people play these games 8 hours a day, and pretty much blow through the content in a matter of 1-2 weeks.
SW has a ton of content, and quite frankly is one of the most polished (at launch) MMO's I've ever laid my hands on. They did a good job, but couldn't keep up with their customers who eat content at a ridiculously fast pace.
I think succeeding in the MMO market is much harder now than back when AC, EQ, WoW made their debuts, the gamer has changed, they expect more content, and they fly through content much faster than they used to.
It also doesn't help that most MMO's today are made to be super easy, you used to have to work to get the high content stuff done, it would take multiple, many attempts to kill a boss. Now all the developers do is bow to the forum spam of crying gamers citing that the content is too hard.
The challenge is gone because the have to appeal to the crying masses, then the content runs dry because people can get to the end without having to putting effort (and time) into getting through the content.
That's my rant, summary:
1. People whine
2. Content is made easier
3. Everyone flies through easier content
4. People whine because there's not enough content
5. Developer screws them self over in a vicious cycle, they can't keep up with new content demands, they lose subscribers.