San Diego doesn't even belong in a conversation with Portland, San Fran, LA, and Seattle.
6 military bases and a conservative base keeps it pretty normal but the best weather in the United States does draw a **** ton of homeless in from all the other shitholes that has poor weather. The homeless problem is just a fact of life when you have the best weather and you can't really stop them from coming. Just have to fund the shelters so they don't run a muck in the streets and river beds. Sherriff's Office routinely clears under passes and river beds. Keeps it cleaned up.
I wonder if you've ever even been to San Diego. I've been to all the other cities you've been to and it seems, especially for Portland, that they embrace and cherish the sight of homeless encampments.
The only complaints I have about my county is that is suffers California taxes and the housing costs. Those things don't make the place a **** hole.