I think there are no pros for proprietary raw.
Photographers have right to their own pictures.
I don't think it is wise to thrust the photo industry to support their proprietary raw formats for archival periods of time.
What I would suggest:
- Photo industry adopts common raw format, it doesn't need to be DNG but DNG is mature and proven
- Adobe makes whatever is needed to support the photo industry with regard to DNG (I got the impression they do just that)
- Photographers would not buy equipment until it is supported by their raw package
I really think that those application that are not supporting DNG need to rethink:
- I wanted to try out DxO because I'm interested in their lens corrections. It doesn't work with undemosaiced DNG. One consumer lost, and I'm not alone.
- Wanted to try out Aperture, they won't support DNG one potential customer lost.
Perhaps not just for DNG but personally it would help tip the balance of "pro" and "con".
I wish people could get equally passionate about viewfinders.