Scenario:

A public Jira is setup for joint venture purposes. The configured roles are
Administrator (projadmins)
Internal (internal users)
External (external company users)

Using the comment security feature an external user can hide comments from other users within the issue/Jira in a project that belongs to internal users/projleads/projadmins.

The permission I suggest is missing is the "View all comments" which should be set to the Administrator/Internal role.

Or: It should be possible to limit the comment security feature to specific roles.