Raising money from a crowd-funding platform could be a very good financial option for small teams and independent studios, but not until there is a substantial amount to show off, moreover you have to make sure you can deliver things before you say you can.
Besides once you go crowd-funding your really have to do things.
Those were the main reasons why I think the Outerra team didn't start any crowd-funding campaign.
Now in the late 2013, the team have done a quite impressive amount of great work that are far above the required "show of" to start a campaign.
The team think they need to provide some basic gameplay first to be more interesting for the general gamer population. But i think it's a misconception of the gamer population expectation. They could very easily start a campaign to raise money for the game engine first that will inject a lot of cash in the project and once they have more money coming in they will be able to get more staff and move things forward at a faster rate.
The Outerra youtube videos have been viewed thousand of times and there are thousand of subscribers, the amount of support they'll receive won't be a problem.
At the moment you can support the project by buying the alpha but it's just no enough to really put the engine on track to it's completion in mid/short term.
What we want to see is an pioneering project on track that have just enough demo feature to make us helping the development of it while dreaming of what it could become.
This project is a very ambitious one, and it would be a shame that it will turn obsolete in the future because it didn't had enough money to be developed quick enough (most likely like the infinity project which lost a lot of it's supporters during 8 years of painfully long development).