The game was released in 2001. In 2003 it had 400,000 subscribers. They released the controversial NGE/CU changes in 2005. It wasn't until 2009 that they shut down about half the servers. And they didn't shut down the game until a new Star Wars MMO was imminent.*
I can't image that most of the market for a Star Wars MMO hadn't tried it, maybe played it quite a bit, and then moved on in the space of 10 years. I understand the desire for things to last forever, but I don't know that most things will.
* Numbers to be taken with a grain of salt, they were culled from wikipedia.