People have been consuming food for a much longer period of time than the USDA has been watching it. When people hear that something could be dangerous or bad for them, they automatically assume the worst with everything. If the same people were told that most of the foods are healthy with no real risks involved eating them they would believe that as well and continue eating them with no concern.
I don't think everything is as bad as they say it is. The world is not going to die if we eat one or two things that have too much preservatives in it. The generations before us got by eating stuff worse than we did and they lived to be older than the generation before them.
I love advertisements for drug companies because sometimes the side effects of the meds seem to be worse than the malady they are designed to treat. Food and drug safety warnings are not overblown and there is no paranoia regarding food safety issues in America. Sometimes, consumers need to be vigilant with regards to things we put in our bodies.
It is my opinion that the warnings and guidelines for food and drug safety are not overblown due to paranoia. Most of the guidelines and warnings are scientifically tested beforehand, and the consequences of not following proper guidelines for food and drug safety are objectively documented as well. These warnings are not to be taken lightly.
The warnings and guidelines for food and drug safety are for everyone's safety. The reason for this is because we get new information each and every year, and we need to update the guidelines. If we didn't it would still be information from decades ago, much that is irrelevent today.