They do when you need to eat. It's significantly different than non-needs.
It'd never get that far anyway. The second you seriously tried to toss all the farmers off of their land, those transporting the groceries to you from other places would park the trucks and let the stuff rot on the dock if they have any brains.
What's to keep populists like you from deciding they can be thrown off their land, and stripped of their livelihood, too?
Only a Californian could come up with such a nutty plan - "Hey guys, because there's more of us, let's make the cities our priority and send all the farmers packing! Who needs em?"
LOL. Amazing. Seriously. That's the kind of stuff that has everyone laughing at you.
The reality is, you wouldn't have to wait for the business owners to do it. Seeing a golden opportunity created by your shortsightedness, other State's politicians would quickly set up a California export tax to be passed along to you claiming "hardships" of some sort to make it all seem quite moral and legal. They'd absolutely love you guys for doing it.
California could respond by taxing movies and iPhones. Uh Oh. We'd all figure out how to do without, pretty quickly. You'd still need food.