If you record in the Shogun, you're not converting to ProRes RAW. You are recording right off the sensor. (Depends on the camera... technically FS-RAW from Sony is mildly compressed...)
But I digress.
The audience is any camera, or recorder, that uses the codec to start with. Any Sony FS owner/op, Canon C300 Mark II/C500 owner, any Panasonic EVA-1/Varicam LT owner/operator or anyone editing that wants a fast lightly compressed raw workflow a-la Redcode - as long as they record to one of the supported Atomos recorders.
That's a fairly decent amount of people in the midrange markets. It's a win.
As for CDNG, you're coming from uncompressed frames to a mildly compressed CODEC, and it's not uncommon to finish in ProRes never mind ProRes RAW; so I see it as a plus. Anyone else who needs an end-to-end uncompressed raw workflow isn't going to use ProRes Raw; but it wasn't designed for them.
And there's nothing stopping camera manufacturers from adding Prores RAW as an option, instead of ArriRaw, etc. I don't know if that'll happen though given the huge investments in ArriRAW and Redcode. But it might... depends on what encoding strategy Apple is using and how costly it is to implement.
We finish in ProRes all the time. I love it as a codec. I'd prefer a ubiquitous RAW format to 37 flavors from different cameras. If it came in natively and performed well. I'd happily use it. But I couldn't see ever converting to it at the start of a job as a workflow unless it runs so light that there were no performance issues. I'm typically in Premiere so I'd be curious to see how it runs there.