Surely that's the entire point of this though to fund challenging proposals.
BTW AIUI all of these proposals have been through some sort of peer review process first. So to get here they've had to be solid enough to survive that process, and I'll be quite a few didn't.
NAIC is to move stuff from almost literally a back of the envelope up to somewhere NASA might consider it a technology they could consider putting in their next mission to wherever.
OT but I've been very impressed by the tenacity and persistence of the Kilopower team. IIRC fission was a $13Bn line item on the DRA 5 study to Mars but they are looking to do a full up live reactor demonstration (minus the radiators) by the end of 2017.
They have also moved the future fission planning baseline from a monolithic 40Kw (the biggest single equipment package that would have to moved in the mission) to more granular 10Kw units that could each be started with a few (space rated) D cells.
As a side effect the more complex (but easier fueled) reactor is estimated to cut power system costs 60% over an RTG and open up options for Ion thruster drive to the outer planets.
NAIC is an exciting programme, in the same way that DARPA's AI work has been. Basically one successful AI application (more optimal load planning of goods on transport ships) has made savings equal to the entire 40+ years of DARPA's AI programmes (and will continue its users money).
If just one NAIC concept delivers that much benefit every penny will have been worth it.