I also avoid the whole Bay Area, and absent a compelling reason, the entire once and former Golden State.
You bring up a good point.
Next thing we know, medical and public health professionals will go to San Francisco to learn what occurs when basic sanitation practices get ignored in a city.
Saves them the expense of going to a third world country!
I try to avoid Frisco, as well. Traffic is terrible in the Preston/DNT corridor, but even worse, it's full of Californians.