It's difficult to understand why Aperture does not offer support for Adobe DNG files.
DNG/RAW files are being used by some camera manufacturers that I work with, and they contain a wealth of metadata as well as the broadest range of image data, including "altitude", which is now very useful in my professional work.
This lack of support has forced me to go back to Lightroom, and to reconsider that application as my primary media catalogue and editing application.
...if DNG is such a 'standard' and I was around when it was originally being developed and presented as a tool for circumventing the various manufacturer nuances, please tell me why, as a standard, Lightroom 5 reads these files just fine, and Aperture replys as "Unsupported Format."
Because folks who call DNG an "industry standard" are wrong. I too was here at the inception of DNG. Adobe wanted to control imagery so Adobe created the DNG format and tried to push the world to adopt it. However Adobe is a software vendor not an image maker, and most of those pesky camera companies including Nikon and Canon rightfully said something to Adobe to the effect of "are you nuts?"
The rationale Adobe made when pushing DNG was "use our DNG and everyone will always be on the same page, the world will be a better place" (coincidentally, tech improvements by camera makers would need to comply with Adobe's wants and needs). Obviously (per the OP's experience that started this thread) every DNG file is not the generic solution stated by Adobe at the inception of DNG. IMO Adobe's rationale was false from the beginning.
Another absurd claim Adobe made at the time was that only DNG would allow image files to read far into the future. As readers for NEF and CRW will somehow fail to exist because Adobe is not in control.
I have been an Adobe user since the early days and own more than a dozen current Adobe products but today the firm makes me a bit sick. CS6 is my last upgrade.