Processed food manufacturers presumably need know the hatch-date for their product, so they can set the "sell" by" or "use by" date at an earlier point in time. It may be viewed as better for business for you and your family to eat the food with bugs in it before they hatch so you don't know how contaminated it is.
Hatch-dates are not important for foods that are wet, pulverized, get embalmed in salt, or get sterilized by processing. You wouldn't recognize the contaminants, or at least they will not be crawling.
Hatch dates may be more critical for nuts and grains with a low degree of processing, such as oatmeal, chocolate covered nuts, etc.