Because then, eventually, you get Chinese-style quality - every company just out to maximize profit, who cares about the consumer.
Inspections are a good thing.
Why would anyone buy a substandard product? Consumers would need to do a little research, the whole personal responsibility thing. And what company would knowingly poison their own customers (plus breach of contract = lawsuits)? Customer satisfaction is good for business, the two go together.
IMO, the FDA is killing far, far more Americans each year than ‘saving’. There is more information on this in that previous link I posted.
The problem is that our inspections are now being carried out by a single federal agency. This performs just as would a single government agency producing the goods. If we replaced it with multiple, competing private inspection services, like Consumers Union or Underwriters Labs, we would get much better inspection coverage. If an inspector went corrupt or slacked off, others would be available to take its place. Right now the FDA has slacked off, and we have no right to choose other inspectors.