Most Starbucks have improved greatly where you can get quick and correct orders.
This airport location is right off the Alaska Airlines flight from Seattle 'gates'. So most folks hit it on the landing or exit to get their caffeine fix.
It is run by only two employees (in fairness, it is a small location so don't think more than 2 can fit without being on top of each other).
They do their best to move quickly but with just 1 person working while 1 takes orders - it can have long lines depending on what time you land.