That you consider trust a genetic weakness is more than a little sad. There will be problems but there have already been fantastic projects that wouldn't have happened any other way.
The question is that is the average case worth the cons? Is the investment going to work out where they are held liable if they fail to deliver anything within x time? How can we dictate what is valuable and not deliveries.
With investors you know who you answer to. Here... not really. The risk is sort of both ways, but one of the two has been eliminated with the donation model.