An inconsistency in the config section ACL resource handling: a non-existent ACL resource is always allowed, but a config section without a resource is always forbidden

Magento 2 config sections are assigned to ACL resources. An example:

The resource tag is not required by the XSD:

If the resource tag is absent then the config section is always forbidden:

If the resource tag is specified but is not exists (for example: Absent_Absent::absent) then the config tab is always allowed.

This is inconsistency.
It would be more consistent to allow access to a config section in case the section has no resource tag:

return isset($this->_data['resource']) ? $this->_authorization->isAllowed($this->_data['resource']) : true;

GitHub issue: 2024