All the companies, it doesn't matter which one, has one main purpose, this is to create profit for it's shareholders. So all the decissions taken are going to be based in this principal objective. To keep the profit increasing, the companies must addapt to new markets and customers, changing their sales trategies and their products. Remember that in a capitalist system competition never stops, so if a company doesn't addapt it reaches banckruptcy.
For fast food companies, schools are a great target because they are filled with kids that are easily catch up by advertising and junk food, school provides a place were parents are not present to limit the amount of food they can eat. In this case the consequences are not questioned as it has been proven that these kind of food is harmful for kids.
