Well your mom would be pretty ignorant in this case. 

Companies explore where the indicators tell them hydrocarbons might be. Just because lands are "open to drilling" doesn't mean there are any indicators that development quantities of oil & gas are present in those areas. Why finish something that shouldn't be started in the first place. 

Simply, if your mom blindly says you cant go back for seconds just because there is something on your plate she is myopic. One must consider WHAT is on the plate first. If the plate has inedible things on it (e.g. napkins, bones, clean corn cobs, watermelon rinds, dirt) that isn't a logical reason to keep you from going back for seconds of edible food.