Its no different than any other dangerous sport.
The death rate for first time climbers on Mount Everest is something like 5-10% (lower now, used to be higher.) People going a second time have a better survival rate but the percentages are still single digits for deaths. And paid guides (Sherpas) get killed every year.
By comparison to adventure space flight, adventure mountain climbing is just a bit cheaper. Do we condemn one and not the other?
How about base jumping? Or even sky diving? A small, but consistent number of planes crash delivering people to the jump point. So adventure sky diving? Do we condemn it as well?
Pretty much any sport we engage in has its dangerous elements and people die all the time (albeit slightly less spectacularly!)