In civilized society, you make a pact with the state. They have a 'monopoly on violence' and in exchange, you and your property are protected. That pact seems to be broken in SF, and to a lesser extent in CA at large. People should do what they need to in order to keep themselves safe. If that means a gun? So be it.
One can fire non-lethal rounds, and aim around a person (or into the ground), instead of at them. I'm not a believer in urban gun ownership. But there are ways to responsibly be one and benefit from it without putting others' lives or your own freedom at risk. (Counterfactual: pulling a gun on a criminal is a good way to have a criminal pull a gun on you.)
i pray i never need it but i'm glad to live in a place that's not without its problems, but where i can at least defend myself and my property.
also @JumpCriscross since his comment is dead: that's silly, you shouldn't make a threat you aren't willing to follow up on. more importantly "warning shots" are a really good way to cause collateral damage. might be you shoot through a wall. plus your eye is on the threat so it's irresponsible to shoot elsewhere bc you aren't actually evaluating what's there and what's behind it.