Put another way, what would global exploration have looked like if sailors refused to accept the risks of early ocean crossings?
What you don't want is a culture that is either a) afraid to take any risk because they are afraid of career consequences or b) willing to roll the dice with bad decision processes due to biases and bad incentives.
Example for a): bureaucrats who are unwilling to push the envelope because a bad outcome would effectively end their career
Example for b): making high-risk decisions due cost/schedule pressure, like competition for a contract
There is no consummate economic incentive for being an astronaut. The incentive is the experience and making some impact on science, and while that motivates many people the probability of attracting the best and the brightest goes down as the probability of exploding goes up.
I'd say there's unlikely to be enough of an economic incentive to justify riskier manned space travel until the earth becomes a whole lot less habitable.
People volunteer for the military, and I don't think anyone's under any illusion this is risk free. The important thing is not lying to people about the risk involved.
They acknowledged this point, though:
>The incentive is the experience and making some impact on science
I think you might be interpreting their last point differently than me. I took it to mean that the "Mars or bust" is an inspiring, but impractical, narrative.