It's a testament to the quality/function of the existing types of ROMs available to uxn and the community that forms around it? Uxn type initiatives are forward-backward looking: how do I ensure future retro compatibility of software created going forward.
It's probably also an interesting challange to implement an emulator.
I was hoping that Uxn could eventually be a vehicle to get rich, graphical apps onto less popular operating systems, like Plan 9 (which they support). While their 1st-party roms are great, the wave of software never came.