Interesting observation which I can see why you feel this way. I would personally classify this behavior you are noticing as a northeast culture thing where people walk with a purpose and not so lackadaisical vs being aggressively anti-social. I walk a lot through the city and I would agree that many walkers (lots probably tourists) do not pay attention to their surroundings (i.e. texting and walking, zig zagging on the sidewalk, or or walking slowly/stopping in the middle of the sidewalk making it difficult for a faster walker to pass by). I would also say that you would expect a city like dc to have drivers that are extra careful and safe due to the abundance of pedestrians and bikers; however that is the opposite of the way people drive here. Drivers in the city are absolutely horrible, and pedestrians are probably not considering the unsafe behaviors of drivers when they walk.