By this logic, Main Street isn't themed since if I took away the building facades and the lights, all I'd be left with is your standard 1950's building.
Or, the Matterhorn isn't themed since if you take away the Swiss mountain facade, you'd be left with a steel coaster inside a tall building.
Or, Space Mountain isn't themed since if you turn on the lights you have yet another coaster in a building.
The point is, CA Screamin does have the boardwalk theme- because of its location, simple queue, and the steel coaster designed to look wooden.