I just ran in to this issue on a site - namely setting "CVV required for backoffice" to 'no' results in it CVV fields showing as 'not required' site wide, ie on all public facing contribution pages.
I found a question about this here https://forum.civicrm.org/index.php?topic=34624.0
If this was the intended and desired outcome then at least the help text and label should be updated.
Noting that on 4.6 this is at civicrm/admin/setting/url?reset=1
At 4.7 it is at civicrm/admin/setting/preferences/contribute?reset=1
What should next step be? Have it perform as described, or describe how it performs?