I'm in the same camp as MasterSezFaster. Many of us in Southern California kind of expect the "big one" to hit. Without notice.
I have all my camping gear (including propane tanks, small cook surfaces propane lanterns, water purification devices) foul weather gear, of clothing, personal hygiene kits, first aid kits, a few gallons of bottled water and prepared packages of dried and non-perishable food all neatly packed and ready to throw in your car within 10 minutes. As a back-up, our boat is relatively also well stocked in case of any emergency. We also keep small survival packages in our cars. Sadly although many of us are prepared, Most (mainly the poor and /or lazy) are not.
I know its easy to play monday morning quarterback: could've, should've, would've in retrospect., But knowing my personality, I would have probably opted to stay. I've been through two relatively minor hurricanes and even those left us with no electricity or water for two weeks. Tthe people of the gulf coast get hit every year by two or three, they were probably thinking its just another hurricane. There are also those that simnply did not have the ways, means or health to relocate or evacuate.