The children playing in a park aren't being political, and are largely insulated from the politics of playing in a park... but those circumstances are surrounded by all kinds of political process. As another commenter said, the park's existence is probably due to politics; as are the rules the children need to follow, what activities are permitted, the safety and maintenance of park equipment and facilities, curfews, etc. It is also a choice on the part of the parents to let their kids play in a park, and which parks their kids play in, and those choices aren't made in a vacuum. Perhaps the perspective of the adult should not be to view children in the park as apolitical, but to be cognizant of the processes that influence their children and try to ensure that they work for the children's benefit.