The nu-vinci is in early stages but it's a realistic alternative to limiting the number of cogs/sprockets you can fit into a space. They've admitted it's currently too big and heavy and are working to change that. I'd hazard a guess that if the housing was removed/changed to fit into a g-boxx there'd be a fairly substantial weight saving immediately.
The Rohloff is hardly traditional, especially when compared to the fairly crap (strumey archer) internally geared hubs that came before. They designed something, pretty much from the ground up, to work as a bomb proof (relatively ) MTB system. I think they achieved their design brief very well.
You say the problems with the hub - I fail to see how minimising maintenance issues is a problem. Especially with a 10-15min oil change (open cap, drain, rinse, close cap, refill) once a year being the first issue you raised.
I do agree on the proprietary twist shifter though - I've asked them to either make other types or take existing proprietary shifter systems and retrofit a double cable friction system into them but no joy there. Now there's a gap in the market for a small machine shop.