Why are `group_vars` and `host_vars` paths relative to playbook basedir?

Hi All,

Can someone explain why ansible.inventory.Inventory._find_group_vars_files() and ansible.inventory.Inventory._find_host_vars_files() are relative to the basedir of the playbook? From my armchair, I suppose it may ensure included plays/tasks/vars with relative paths always resolve to the expected file.

Thanks for taking the time!

Kevin