So some say.
I think not.
When we operated the Space Shuttle, we killed two crews in 135 launches, a fatality rate like a bad year on Mount Everest. Nonetheless, Congress and NASA tolerated this every year for thirty years, even though we had, like the Soviet Union and later Russia, known how to do much better for decades.
We now plan to make the first manned flight of the Orion spacecraft on the second flight of the as yet unflown Space Launch System. This is not risk averse.
I don't think we as a nation are generally unreasonably risk averse about space. Our manned space program is currently heavily dependent on pride and prestige as a motivation, because our manned program hasn't figured out how to do anything particularly compelling in low earth orbit, and going further is extraordinarily expensive and without immediate economic return. That's OK. I'm proud of our share of ISS, just as I'm proud of the Lincoln Memorial and the Statue of Liberty, and I'm willing to to pay for that pride.
The flip side of this is that killing our astronauts is unusually costly to our pride and prestige, because they die when everyone is watching, or when their deaths are replayed again and again. We hate it when that happens. It makes us sad. Since we're paying for the program, it makes sense to do it as rarely as reasonably possible.
I think that excessive fear of people dying in space is most often deployed when NASA and members of Congress with NASA centers in their districts want a superficially plausible reason why NASA needs to continue to own and operate its own space launch system. Of course, they would want that, for institutional and political reasons, but the argument doesn't bear close examination.
Arguments that the NASA launcher will be significantly safer have been based on NASA's own reliability estimates, which have consistently been biased in favor of NASA launchers and against non-NASA launchers, and have been shown to be so when tested by experience.