That's not what he said or implied, he's merely responding to your argument 'Donating any amount of money to prevent people you don't know from marrying each other'. I think you might have a justifiable argument here, but it's not clear at all to me what it is.
I cannot imagine the mental model you're working with if my observation is not crystal clear despite omitting the word "adults" in my initial post. Both your and Y_Y's responses read as bad faith to me, but it could be extraordinary ignorance.
In either case I have no idea how to make it clearer for you. Good luck.
