Remember the Tiger Brands fines? So did state intervention prevent their dodgy tactics? And how has the state fining them helped to stop their dodgy practices? 

The risk of mass poisoning is greater when a larger chain has poisonous or contaminated products on the shelves in any event. But they also have more to lose. So let's not get rid of state intervention? OK but then there's the 2008 Chinese Milk Scandal. Note how the government was not only involved but some governments were complicit in covering up the scandal once it emerged.