But it's not. We're more than happy to throw human lives at most things. Any sufficiently large civilian project (much less anything military) will have a greater-than-zero expected death toll from accidents, on-the-job medical issues, etc. And arguably this is the right way to make the omelette (although we've definitely improved in the past few decades: https://www.forconstructionpros.com/blogs/construction-toolb...).
It's only when we get to space travel that we suddenly become shy about the human cost of progress. It's big and dramatic and failures are very public. Arguably we should be willing to take much greater risks at this point to establish ourselves as interplanetary.