Here's what I don't understand. I live in DC. There's plenty of homeless people. I see them every day. But there's very little pooping in the street. Likewise in NYC. Homeless people? Sure. Poop in the street? Not so much.
Neither place, in my experience, has an abundance of public bathrooms. There's almost none that are truly public, like a building specifically with a bathroom for the public to use. Most fast food places and coffee shops will have a lock on the door with a code so you have to buy something.
So why is it just San Francisco that has so many people pooping in the streets?