Like I said I'm a different reply, It's not in anyone's best interest for me to go 15 to 30 mph below the flow of traffic just because I ended up behind someone who doesn't know they're on Earth much less operating an automobile. If there's a legal way to pass them, I'm going to. Once they're behind you, you only have to worry about getting rear-ended at a stop, which is only an issue in slower city traffic where it is easier to keep an eye on someone behind you. In which case, just stay in the lane you used to get around them.
If they're driving erratically, however that's another story and I definitely agree that I want to stay as far back from them as I can. But they're usually speeding and my whole point is centered on the premise of being stuck behind a slow inattentive or otherwise neglegent driver. They don't even need to be a bad driver, maybe they're new to the area, looking for parking, having a medical issue, etc. Just pointing out that not all overtaking is about getting there first.