You just need to adjust your point of view in this matter. Swtor's update schedule is not particularly slow, it's just that every other Game Developer is faster.
And being fast comes with many disadvantages, that you will never see in Swtor.
- Content mets always the highest quality standards.
- Content is always bug free
- and so on...
But most important, fast means in most cases only raw manpower. Paying a lot of employees to create content will dimmish the profits. And Swtor does not do this.
If you have a team of 3 people working on new content, instead of the standard of 100 people like in other companys, almost all of your income is net profit and you don't need to share it with your subordinates.
Sooo... long story short... while Swtor is gaining massive amounts of profits with it's approach, other MMOs basically don't make any profit at all. That's why Swtor is basically the only MMO that is still in existence after such a long time.