Personally I think the risk aversion has less to do with parenting and more just life experience. For the vast majority of human existence, high child mortality was much higher than today. Even for the wealthiest, watching some of your siblings die was simply a fact of life. It was only in the early 20th century that childhood death became uncommon, and even then these kids were being born to and raised by people who had grown up in such a world. My grandfather, for example, was the youngest of 12 and grew up in a household where no one expected all 12 to make it. The combination of an excessively large number of people and the desensitization to death (with maybe a little bit of lead paint thrown in for good measure) naturally leads to the view of life being cheap. These are the sorts of conditions that make wars that cost tens of millions of lives conceivable, but also the conditions where people are okay with being strapped to a rocket with only a bit of testing. The baby boomers were really the first generation raised entirely with the expectation that they would live, and late genX/early millennial children were likely the first in history to be raised by parents who had been raised with that mindset. The longer you expect to live, the more sensible risk aversion is.