I dunno, half the popularity (probably more) of the recent high-wire walking and skydiving without parachute reality specials was the chance that the star of the show may die live on tv, so it's not without precedent.
Filming a reality show about the first attempt to colonize Mars may be grim/depressing live, but could probably be recut into something watchable without setting the space program back 100 years. Not like it's Hunger Games and we're selecting people to die, frame it more as brave struggle of early pioneers that know the score going in.
Not pushing for it, exactly, but at least there would be more to offer than a real-life Survivor and death porn...
If this ever comes to be there can be little doubt that it would be the highest rated reality show ever produced. Everyone would watch it. That said, I hope they don't.