Asking the real questions outchea. I've seen so many bad answers over the years. That it's situational awareness and so people can't jump out of alleys. That it's because the sidewalks are bad (they are, but do you want a twisted ankle or an SUV to clip you). That it's to be able to see the bus. I guess I like that one the best. The explanation I like the worst is that it's so people can pull car door handles. I've seen that from walkers and bikers.

I think I want to ask the next person I see doing it. Curiosity killed the cat. Fortunately, I am a human being and not a cat.