It’s aimless because we (I’m assuming American) have decided to drop the one thing public schools were actually designed for: creating citizens that share a common national identity based on having learned the same things and values. It’s a tool of nationalism, and when you forget or willfully expunge that half of public schools (the other half being the creation of a populace that is decently educated enough to engage in civic society), shit starts to look pointless.

Edit: As an example of this, most Americans can recite both the pledge of allegiance and a canon of children’s rhymes — yankee doodle, mary had a little lamb, etc. Knowledge of which act as an immediate shibboleth to others that you on some level grew up American.