Since I also live in that area, I can see what he sees, which is what the homeless, mentally ill and desperately poor look like when they’re home(less). The new “techie” area is encroaching on the Tenderloin, their home ground (i.e. where they segregate themselves), so of course he’s going to see them. And yes, it’s between the business district and the city center.
Oh, and by the way, that’s also where the working class has to hang out, prices in the city being what they are — or was he thinking that the “working class” has incomes like his?