COPPA feelings

Once upon a time, in 1998 to be specific, The United State's Congress enacted the Children's Online Privacy Protection Act (COPPA), which does pretty much what it says. It protects the private data of children under 13 that use online services and requires that content on the internet made for children abide by strict rules and regulations.

This is why pretty much every general online service out there, YouTube included, makes you check a box verifying that you are over 13 before allowing you to make an account.