I'm not saying that we need to do super intense cost benefit on every way of preventing death. But if we are spending far more to prevent a particular type of death than another just because of public sentiment I think that is a problem we should fix.
And doing that kind of analysis can actually save far more lives by using resources more efficiently. Orders of magnitude more people die from obesity than terrorism, yet we don't spend orders of magnitude more money on promoting healthy lifestyles. Or to pick a slightly absurd example, if we replaced security screening with cancer screening it could be far more effective in preventing people from dying in ways that aren't their "fault" (false positives aside).
What about when you measure the costs as lives vs. lives? E.g. spending X dollars on airport security saves Y lives, but spent on highway safety saves Z lives.
I can only speak for myself, but I'm not a fan of cost-benefit analyses when it comes to human lives. Going down that route gives us such wonderful things like corporations preferring to pay out damages instead of making product recalls (c.f. the Ford Pinto case). It gets quite cynical. But I guess in the minority here. All my "tech bros" think like that too. It's all about cold, hard statistics.
There is something to be said about "Vision Zero[1]" type projects, but as it stands I don't think the TSA is currently engaging in a deliberate such project.
[1]: https://wikiless.org/wiki/Vision_zero