Frankly I think that level of privacy control has little appeal to the mainstream. You could of course argue that modded Android ROMs also have little appeal to the mainstream, and so adding non-mainstream features to modded ROMs is cool. (And I'd totally agree with you.)

But I suspect that Kondik might aspire to get privacy features like this into AOSP. Something like an all-or-nothing incognito mode has precedent in places like Chrome and Firefox, so I feel like something like this would have a reasonable chance of making it in. A fine-grained permissions system likely wouldn't.

However, I personally would like a little more fine-grained control. I might trust a location-centric app with my GPS (or at least recognize that the app is useless without it), but not want to give it access to my contacts.

Note that CM7 did have a fine-grained permissions system. It wasn't as extensive as OpenPDroid, but you could flat-out reject individual permissions given to apps on CM7. Unfortunately it often caused crashes, as the apps weren't built to be denied so harshly. The fake-/no-data approach of incognito (also one of the options that OpenPDroid offers) probably won't cause any compat headaches.