I wonder how much this has to do with an increase in people knowing that there exists a system to complain about poop, versus the actual increase of poop itself.
No, it was definitely a problem then. I was working in mid-market around then and we definitely noticed when the mechanical sidewalk sweepers missed a shift. Impressively it's gotten worse.
Are you not looking then? SF isn't even the only place in the Bay Area I've seen shit on the sidewalk.