Maybe it's just another thing that's eroding in society. Vicseks collective motion claims that a crowd of people moving in random directions subconsciously plot a route that will avoid collision no matter how dense it is.
If that's true then the only reason to not step around another person to the right (the accepted norm in Western society) is because you naturally move left or, you come from another society that moves left as the norm. The children of immigrants will learn their behaviors from their parents and then adapt to the conventions of their new environment over time.
I don't know if I used to move left (British immigrant) and re learned. I's been so long since I lived there but I know it's hard for me to not automatically move right now.
It's also a presence thing. Smaller people normally yield to larger ones heading toward them as a defense reaction. Even to the point of moving the "wrong" way because they calculated that motion as the easiest path of avoidance. Sometimes people that would naturally yield consciously do not, in order to prove a point to themselves I guess.
Maybe it's a Napoleon complex?
I would think that it's more about something that I have remarked upon frequently; "the new sociopathy." People are all about themselves now, with no day-to-day consideration for their fellow man. I say this because of the number of people who walk right at me when there is plenty of other room available while they're tapping at their cell phones, pretending to be tapping at their cell phones, or making a point of looking anywhere but at me.