That's surely a very good point. However there's also presumably the danger of small projects getting so bogged down in adminsitration that they never get started.
Would a simpler solution maybe be to just keep money paid in trust to a third party until the project is completed or some milestone is reached?
As a separate issue, it's interesting to see on the SkyOS page that the SkyOS team have currently donated more money to the projects than the community. It's good that SkyOS are themselves investing in a software base.