Donating to a dev is definitely not a matter of greed & profit, since you bare the cost and everybody enjoys the reward together. Let’s not pretend these are good incentives.
Devs may ask for financial help but it would be foolish of them base the entire project’s development on it.
Let’s not forget this is open source software. If nobody wants to work on it for free in his spare time, it deserves to be forgotten anyway.
Keep in mind some of the miners themselves like the freedom to decide when and, how much to gift themselves; could be that the most giving of them all could come from that pool later in time.