It sounds good on paper.
IPVM has done reports on the lifespan of an SD card when written to constantly and it isn't pretty. Some of the cameras monitor the storage and can output a message when the SD card has failed. Otherwise, how would you know?
New NVR's also provide PoE to the camera. Unless a separate power supply is run to the camera, when the NVR is stolen, so is the camera power so you only have video to that point. Maybe it's enough, if the camera allows multiple power inputs at the same time.
Imagine having to replace a few hundred defective SD cards, in the cameras.
Several times a request has been made for "cloud storage' or a second NAS and other ways to combat this issue. Some just put a dummy DVR/NVR in plain sight.