I'm assuming that since a single receptacle is all that would actually required, that this is generally why we can use a duplex receptacle to do double duty like this.
The beginning of 210.52 says, "the receptacles required in this section shall be in addition to any receptacle that is"... [2] Controlled by a wall switch.

Anyway, my purpose was mainly just to confirm as to whether or not my suspicion was correct, that being, although this would be a poor arrangement, it could actually be considered as a code compliant installation.
I think the whole matter could have easily been clarified with minimal effort in 210.52[B],1, Exception, by just adding something as simple as... "Receptacles installed using this exception shall not be considered as meeting the requirements of 210.51[A],1".