I don't know if you are specifically talking about Washington State, but many states have city income taxes. I live in Ohio and almost every city has an income tax (I have to pay 2-1/2% of every dollar I make to the city in which I work).
I'm originally from The People's Republic of Kalifornistan, and even they don't have municipal income taxes.
You're telling me that a fast food worker in Dayton has to pay federal, state, AND municipal income tax?