there's a lot of projects and people behind them who are thinking short term instead of long term
Thinking long term does not help, unless there is a definitive plan on what are going to be delivered - every long term must consist of clear break up of shorter milestones and commitment around that. Talking long term without definitive plan is useless.
The DHF and open source. These two go hand in hand because if you're going to ask for funding from the DHF you're going to want to have the project be open source in case something happens along the way. This is the trust factor.
Well, Open source definitely helps in the trust factor, but getting the DHF may not be directly related to that. There could be a good open source project, but still not got DHF. I have heard that its because of interest of large stake holders, and only those get funded, who have some kind of association with them ?