There is no point in adding 48kHz PCM audio in a heavily compressed H264 video file to be send to the client.
Forgive me if I'm misunderstanding, but there is every point in adding uncompressed audio to compressed video.
I completely agree that Nuendo should not be a video editor! That is indeed the job of Media Composer or Final Cut.
But every day I send high quality audio to directors sync'd to a preview quality video so that they can hear what I've done in relation to the picture. The picture can be low quality. The director is assessing the sound and how it fits with the picture, not the quality of the picture. If the director is happy, then I can pass the audio file to the editor to drop on the picture timeline, or send audio stems as part of a package to the dubbing mix.
Copy video rather than transcode would be fine for this purpose, as neither I nor the director care about the quality of the video during this back-and-forth passing of drafts.
I do this every day, as do many of my colleagues. The difference is, my colleagues tend to use Pro Tools, and so when they create the video previews with uncompressed audio they do it straight from Pro Tools. They don't have to faff around with Quicktime Pro just to provide a director with good audio against low quality video.
This capability would not erode Nuendo's audio only pedigree. It would just bring it in line with what Pro Tools does and what a lot of users need every single day.