I suspect it will still feel altruistic; I think there's not much difference between tax credits and a medal. I find it improbable that the altruistic motivation would fall off in some specific non-linear way such that the overall motivation would be lower. At least, you must admit that this bears trying. Even if there's a 50% chance you're right, there's still a 50% chance this solution will significantly help.
I suspect it will still feel altruistic; I think there's not much difference between tax credits and a medal. I find it improbable that the altruistic motivation would fall off in some specific non-linear way such that the overall motivation would be lower. At least, you must admit that this bears trying. Even if there's a 50% chance you're right, there's still a 50% chance this solution will significantly help.