We've observed that our Community Members/Campaign Owners are divided over the value of downvotes. Some feel downvotes provide valuable data and added rigour to a discussion, others feel the potential for downvotes discourages participation.
One of our priorities as Administrators is providing a consistent and intuitive user interface. Perhaps if the potential to turn off downvotes could be decided at the campaign or funnel level (instead of being an 'all or nothing' global setting) this could give us more tools for owners of private campaigns to respond to what are sometimes unique needs of their audiences.
From a consistency perspective this might also be an acceptable compromise in that Campaign Owners could manage the 'different looking' interface with their private group without impacting the majority of Community Members.