OK I think you're missing what I said. The incentive is not altruistic impulse + money, it's altruistic impulse OR money. So far most of the Tor nodes really are run on charity!
"As it stands I wouldn't be surprised if the majority of nodes were operated by various national intelligence agencies simply because they have vastly more incentive to do so than anyone else. Potentially being able to profit from this changes things dramatically and gives people who wouldn't consider themselves stakeholders actual reason to 'sell' their bandwidth to the tor network."
It's possible that most of the nodes aren't run for altruistic reasons at all. And are in fact run to datamine the network to discover the identity of people using it.
Paying people won't affect the people who are doing it for altruistic reasons alone, their price is already met. It's just an added bonus for them. But it will have the affect of bringing in additional people who wouldn't have considered it before. The only problem with the daycare's solution is the fact they didn't charge enough to offset the "cost" of feeling bad about being late. To the customers it was a worthy exchange.
Similarly, the tor coin needs to have a value that will offset the 'cost' of feeling bad about not contributing to the network which I know is extremely low.
In the example, the parents picking up their kids on time beforehand were doing so for altruistic reasons alone. When the choice became framed economically, parents started picking up their kids on time less often.
You say they need to raise the fine, but the point here is that it's not economically feasible to raise the reward for running a Tor node indefinitely. The max amount paided out for running a node may be less of an incentive than the existing prosocial incentive to do so.