Who ever designed the modern San Francisco gets the idiot award.
Perhaps (if by modern you mean the leftists in charge for the last 30 years). The original designers back in the 1850s actually did a good job, when the town grew from a few hundred to hundreds of thousands overnight. There was lots of unregulated growth, where tons of garbage and refuse was dumped at the bayshore and that landfill created new real estate to build on. That's where the earthquakes do the most damage.
The current city leaders have been slow to fix the water mains - most of them are over a hundred years old and break on a regular basis. When the big one hits, there will be no water supply to fight the ensuing fires, or water for the survivors. I drove co-workers to the Marina district in SF after the 1989 earthquake hit and saw the fires there; scary scene. We're not much more prepared now than then.