If I'm going to wait for a car to pull out, at the very least, the engine has to be running. More likely, I need to see backup lights. If the engine is running and I don't see backup lights in very short order, I move on. From the point of view of the parked car, I frequently like it when a driver stops and waits, as long as I don't feel pressured to get the hell out of Dodge. As long as the car isn't too close, it becomes easy to back up safely. If I'm the driver in the parking space, it's very likely that I don't know that someone is waiting. I have cars, and if I'm parked next to a taller vehicle, it's not unusual for my view to be completely blocked. When backing up, I don't care a lot about the direction where I ultimately want to travel. I'm fine with re-orienting myself once I'm out and moving forward. There's often a direction that's physically easier for backing up due to the way I pulled into the spot, so I prefer to go that way if I have the option.