Hmm.. That's not bad for 4x4 channels IF the preamps are clean. I think the Grace M208 (8 in, 2 out) is $3K once you buy the dante card. Although the MD-4 is fixed at 48K. Still, for the TV/Film production houses this could be great, they all work at 48K anyway.
Yes, it may be simply not enough user demand. I don't know anything about the cost to increase the SR to 96k in any Dante device; processor power and so on. But the newest Dante chips come ready to roll at 96k and I can't imagine that the cost would be enough not to just "make it so." Seems like small thinking to me, but anyone with more knowledge of what it takes, feel free to chime in.
PS. I will own that this is a MAJOR pet peeve of mine.