If the FDA/USDA REALLY DOES test our food, why are there still diseases in our food? (like salmonella)?

They claim not to have enough employees to check all the processing plants.I say BS.Like everything else they have to have a cause to act.I say they aren't doing their job.Have you ever heard of any advertisement offing this job?? NO. And neither have I.Although some things can be contaminated from the growing process most is in the handling of the food itself.It only requires a clean work place so now many aren't doing their job.I think we all should complain and loudly.My grandmother canned and we never had one single thing spoil because she was adamant about the whole process,from the jars to the cooking and how clean everything should be.She used a pressure cooker and a wood stove so there was no real regulating of heat but she still managed to get the job done right.Alot of the blame goes to the workers themselves.People have lost pride in a job well done they say well the company is rich they can take a loss,that attitude is everywhere,I don't think this problem will get solved anytime soon.