It is jealousy and insecurity.
They hate us because we're the 5th largest economy in the world. They hate us because our farms are far more productive than theirs...we don't say "apples or oranges" in this state because we can grow both. They hate us because we go swim in the ocean in the morning, and ski in the slopes in the afternoon. They hate us because we are fashionable. We had shopping malls, automated banking, drive-thrus, and i-pods long before the rest of them... and they can't stand it.
And it's not just SoCal either. It's California. Period.
If you said you were from NorCal, they wouldn't like you anymore than before. They'd just come up with a new set of stupid stereotypes to hate on you:
"Superficial" becomes "Socialist"
"Self-absorbed" becomes "Hedonistic"
"Snootiness" becomes "Stuck up"
"Body Fascist" becomes "Tree-hugger"
"Hollywood liberal" becomes "San Francisco liberal"
And "Materialistic" becomes...um... "Materialistic"