[Strangler Lewis]

I don't think aggregating it is a sensible way of addressing what the responsible approach of each property owner is.

Our idiot prior owners planted sequoia trees on our .11 acre lot. Very pretty. Totally inappropriate for the lots. One of them had a split trunk, to make matters worse. The trees are an inevitable hazard to driveways, fences and, eventually, rooves and brains. We just spent about a thousand having them out (to the indignation of our neighbors who called us tree-hating cretins but said that, no, they would not sign a perpetual release of liability)

We felt that spending this money now was the responsible thing to do even though it might take ten years for the one tree to crush our neighbor's house and, even then, they might not be inside at the time. If you frame the question as whether a property owner should spend one thousand, five thousand, etc. to alleviate a clear risk of harm that would result in far larger liability, then the decision becomes clearer. Aggregating the effect of that decision among everyone in the country who has a similarly costly risk on their property shouldn't distort what the right thing to do in particular cases is.