The US Post Office powers decided long ago when they started losing money that having better customer service and hiring more employees would not help bring in more customers, so those of us who still snail mail are punished by long lines and lone clerks. This location in particular is designed to protect the single clerk from a customer with a nuclear warhead, as the post office powers also decided to take it upon themselves to draw the lines between neighborhood classes in the most obvious and stereotypical ways possible.
Honestly, the clerks in my experience are probably underpaid and under trained, but I haven't found them to be rude or unpleasant. They're stuck in a bad situation, but everything I've mailed has gotten to its destination clean and complete. That's all they can control, and they do pretty ok.
No kiosk, but parking in front. Trade off.