In many states the housing market is unaffordable for most. In an expensive area, a single ANYBODY with a large mortgage is subject to being let go from a bad economy, downsizing or whatever. So, though RE is a great investment, there is no guarantee you won't lose it all.
If a single person is fired and can't find equal pay in another job, the house could become forfeit.
The market is always crazy in socal, but you can still find a house in a semi-decent neighborhood, if you don't mind an old fixer upper.
That's why even with a $65000/yr income I am looking at homes under $120000.