No. 71% of San Francisco's homeless population once lived in the city: http://sfist.com/2016/02/11/71_of_sf_homeless_once_had_homes...
"Seventy-one percent (71%) of respondents reported they were living in San Francisco at the time they most recently became homeless, an increase from 61% in 2013. Of those, nearly half (49%) had lived in San Francisco for 10 years or more. Eleven percent (11%) had lived in San Francisco for less than one year."
What are these "development reasons?" Airbnb? Property owners have had no issue knocking down buildings in places like the Mission to build high-rent properties in their place. There is ample opportunity to satisfy demand for low-to-middle income housing by building upwards which developers choose to ignore in favor of satisfying the rich.