As BewareOfTheSharklets says, biosecurity rules are not trivial make-works for bureaucrats. In any region or country that depends on agricultural production, especially fruit, the introduction of a new pest can cost millions--perhaps billions--of dollars. And it's not just air travel: on the roads leading into Victoria in Australia, for tens of kilometres there are huge signs warning of the vegetation quarantine to keep out fruit fly, and the people at the border are serious about it. California is heavily dependent on its fruit and vege production. Perhaps they should publicise their biosecurity rules better, if they often have problems; the cute beagle puppies that ruthlessly find vegetable matter at Auckland Airport do double duty, by detecting and by being adorable about it. Fixes the rules in the mind of the traveler, in a pleasant way.