Under the current default Settings, capacity planning is turned off. Our site would like to have the default ON, and to have the default to enter effort at the requirement level.
The capacity planning feature is purposely available at the product level, to allow each Product Owner with the ability to specify whether they would like to manage their product with capacity planning in mind -- without the need to contact an Account Admin to make this change.
Because of the greater flexibility and ownership provided to Product Owners, we are unlikely to make changes to make this a global Admin user setting.