Stop and Go. And Stop. And Go.

What's with the World Trade Center stop on the Silver Line?
The bus stops to drop off and pick up passengers, drives about 4 feet to a stop sign, stops, then proceeds up the ramp out of the tunnel.
This is isn't a normal tunnel portal, it's more like a huge open garage, and you can see from the station all the way to D street.
Why not make the standard drop off/pick up area at the point of the stop sign?
There's still about 15 feet of station at that point, so it's not like passengers would be walking on the ramp or anything.