The bedrock of their economic calculus is a disbelief that they could ever possibly net profit by spending on other people. As I said in the last paragraph of this comment, it is their concept of society itself that is limited/constrained in scope, and that has nothing to do with money.

You’re weighing the cost of fixing a problem now vs later, and they’re clinging to the idea that because they’re not the victims of that problem (currently nor in their own optimistic projections), it would be best to simply never solve it at all. But talking about cost to (an intentionally vague) us is generally more acceptable (and compelling) to a liberal society than its counterpart – dehumanizing whomever currently pays it.