Minors in a court

Minors (those under the age of 18, in most states) lack the capacity to make a contract. So, a Minor who signs a contract can either honor the deal or void the contract. There are a few exceptions, however. For example, in most states, a Minor cannot void a contract for necessities like food, clothing, and lodging. Why would Courts carve out these exceptions for Minors? What is different about these types of Contracts compared to others?