I think a lot of these coin-incentive models are really ways of getting "rational economic actors" to put their money towards socially beneficial causes. Sure, we might each be willing to throw a few bucks in for Flint, but are we going to hit $300 million? By adding a market mechanism, the hope is that creating infrastructure could be just profitable enough that the general public, and any private investor, might see it as a reasonable place to park their money.