Do you feed your dog human food?

I just met someone today who was shocked I feed my dog table scaps, cookies, pretty much anything I eat. She said she's never fed her dog anything but dog food and how unhealthy my dogs must be. One of my dogs is going on 16 this November and my other dog is 7 with no health problems. My oldest dog is getting cataracts and losing her sight but other than that she's running around still. Is it really that bad for them?