I don't know why you think Noe Valley is covered in poo
I found that observation a bit odd. The part about North Beach being clean was also a bit suspicious. Whenever people make blanket claims about how dirty SF is, I wonder if they've ever been to the western half of the city.
If Noe Valley is covered in poo, at least it's dog poo.
I've never seen anything too disgusting in Noe Valley. The main principle of distribution of filth in San Francisco seems to be this: homeless people are too lazy to climb hills.
I lived near 30th and Noe (on Harper). Harper was clear. It was way up on a big hill. The bottom of the hill, 30th, Church, Dolores --- great Chinese food, filthy.
My point was, I lived in really crappy SF, I lived in hipster urban SF, and I lived in residential SF, and they were all filthy.
I don't know why you think Noe Valley is covered in poo, though. Noe Valley seems no more or less filthy than the nicer areas of the Castro.