Living in San Francisco we are pros at coexisting with homeless too. But this "tent-city" atmosphere is a crazy phenomenon. My office just moved from the financial/hotel center of town to a slightly more light industrial part of town and on my walk to the office I pass by block after block of people who have erected tents on everyday streets. Some even have generator's, some have Christmas decorations setup on their tents. It's sad, amazing, disgusting, scary, humbling all at the same time.
The city is making real efforts to solve the problem without 'cracking heads' because generally the population of west coast doesn't have the stomach for a tough approach.
The weather isn't quite as nice in SF relative to LA, but it is still a more realistic place to be homeless than most other places in the country. Addictions and mental issues are at the core of 90% of the people in this situation, so it's hard to get MAD, but easy to get sad and frustrated.
This is a google street view from a couple blocks from my office. And it is about 3x as bad now. Every open curb space now has tents, and about 50% of the sidewalk is taken up, so even walking by can be difficult.
Ironically some of this growing problem is a result of shuffling the homeless around in advance of the "Super Bowl City" event that took place the week or two before the game last winter. They keep this shit out of purely residential neighborhoods, and part of the tourist/financial district, but anything in between is getting overrun. And keep in mind to live in the neighborhood from the image I posted probably costs you about $2500 for a one bedroom apartment (if you are a new resident). Crazy times.