I guess it will change with time...
With space travel, it's both expensive and inaccessible other than to those who could be regarded as among the 'best and the brightest,' and whose loss is felt disproportionately. A better contrast might be that we (in the US) have a moderately high tolerance for deaths in war, because the bar for entry into military service is not so high. But if you recall the early days of the war in Afghanistan, there was a big freakout over the death of Corporal Pat Tillman, who abandoned a promising career as an NFL quarterback to serve his country post 9/11 and then died in a friendly fire situation during combat. It's very hard to become quarterback in the NFL so his death was considered a great loss, even though morally it's no different from the deaths of thousands of other soldiers. So deaths on a Mars mission would provoke a reaction of 'why are we sending our best to die in the cold wastes of space/on the surface of distant planets when we have perfectly serviceable robots?'
I think the way it will change is if privately financed asteroid mining becomes a practical reality, in which case deaths in the line of work will be considered tragic but acceptable (within reason), much like deaths on oil rigs and other high-risk industrial environments.
When you are talking about spending many, many billions for a single mission, arguably the success of the spacecraft is worth more than the lives of the humans. If the crew is at a significant risk of death, and it is worth noting that a lot of these risks would affect the crew mostly evenly, then the whole mission is in jeopardy.
https://en.wikipedia.org/wiki/Value_of_life#Life_Value_in_th...
Because of the diminishing returns to safety spending, it's generally better from an economics perspective to accept an order-unity chance of failure and just send multiple missions. But obviously, this is not how we design human space travel.