Microbial food safety assurance

Most people know the basic rules of food hygiene, don’t they? We teach our children to wash their hands after going to the toilet, we know to keep left-overs in the fridge and to cook, or at least wash, raw foods because they might be contaminated with ‘germs’. We cover foods, we avoid mixing cooked and raw and, if the food is old or we’re not sure about how it’s been stored, we apply the old adage of “if in doubt, throw it out”.
They’re simple rules that reflect our awareness that invisible microbes might make us sick, to minimise contamination of food and limit growth of those organisms if contamination occurs, or to kill them before we eat the food. It’s hardly rocket science, is it? And if these are simple rules that ordinary people apply, how much safer must it be when food professionals prepare and process foods?