A one-word rebuttal: weather
I could rebut with the single word earthquakes, was even in Silicon Valley when the 1983 Coalinga earthquake (https://en.wikipedia.org/wiki/1983_Coalinga_earthquake) hit.
Then again, I was also retired to my home town of Joplin when the 2011 tornado hit (http://www.ancell-ent.com/1715_Rex_Ave_127B_Joplin/images/), but one convenient thing about tornadoes is that you only have to walk a few blocks perpendicular to their line of movement to get to undisturbed buildings and such, the aftermath is therefore a lot easier than wide area disasters like earthquakes and hurricanes.
Slipping on the icy stairs in Chicago where I grew up and lived most of my life, before walking to the train and having my glasses frost over from my breath did it for me. Then there are the insane humid summers.
Being able to go outside practically whenever I want and not feeling guilty if I stay indoors was worth moving to the Bay for me. We also have gorgeous long falls here where the leaves change color and everything.
Don't underestimate how many people loathe crappy weather.
What? I'm from Seattle, seasons definitely change there. It's as "west coast" as you can get.
Seriously though, I moved to Seattle from the Southeast, and I actually love the predictability aspect of the weather here. I rotate between the same hoodies for 9 months of the year and never have to check the temperature before heading outside, it's always 50-60ish if it's not summer. So while technically it "changes", it doesn't compare to the rest of country which can have some truly nasty extremes I've never seen here.