I don't know if this is true for many people who live here. There is a subgroup of my friends who live in the city and will drive almost every weekend for 30-60 minutes with their bikes and kayaks for recreation. If you avoid the popular trails and rec areas (e.g., Muir Woods), you can get somewhere very peaceful fairly quickly. I think the balance between city and access to nature works for a lot of people who live in the Bay Area.