What is stopping you from starting a kickstarter campaign to make some improvements? How about using it as a support/donation tool rather than selling a game?
Kickstarter's
Project Guidelines, for one thing.
I also get the sense that the team doesn't really have an obvious way to turn cash into progress—no one's working on it full-time, and it seems impractical to build up a sufficient endowment to let someone quit their job and go full-time. IIRC it was mentioned somewhere that modeling and texturing is a bottleneck, so potentially funding could be put together to hire a specialist for some specified amount of work, but that gets into messy administrative things that you then need to convince someone to take on.
Edit: actually, that would probably work (say, a campaign to fund a new alien race or something)—the main issue there is that that's the sort of thing that can rob motivation from people already contributing or considering contributing for free. Not guaranteed, but it isn't risk-free.
~J