Thoreau begins Civil Disobedience by saying that he agrees with the motto, "That government is best which governs least." Indeed, he says, men will someday be able to have a government that does not govern at all. As it is, government rarely proves useful or efficient.
This statement is ironic because they ARE a crowd of kids.
Piggy is angry because they are acting like kids, but they are kids. Piggy expects them to act more maturely than they are capable of doing.
It is statements like this that contribute to Piggy's being an outsider. He continually places himself "above" the others and criticizes their behavior, much like an adult would.