Just because developers name libraries things doesn't make them accurate. Generally when something is misnamed it's because of backwards/intercomaptibility or just design decisions that differ from original implementations and it's no longer feasible/reasonable to refactor to a different name.
Examples:
windows 7 was version 6.1, windows 8 was version 6.2, windows 8.1 was version 6.3
Java 5 was versioned as 1.5, continuing the convention from previous releases 1.2-1.4
Hell, where I work we use an automation workflow with functions called stuff like "create_and_assign_citrix_security_groups_to_static_containers" that has long since been adapted to work with vmware and other non-virtualization platforms like k8s. Refactoring those functions would mean refactoring any external automation that uses these libraries, just like refactoring versioning schemas would break compatibility with any external software that relies on an assumption that windows >xp would be 6.X.