One death isn't too many. It's a matter of too high a probability of general random catastrophe.
Example: Astronaut Tim goes on an EVA to perform an emergency repair after a micrometeorite damaged the space station. A malfunction of his space suit kills him. Everyone agrees that Tim died a hero doing a high-risk activity that needed to be done, and almost no one would say it means we can't do spacewalks or can't send astronauts to space anymore.
Compare to Challenger or Columbia: The whole crew dies randomly on the way up or down during a routine mission. A program which became known for having like, a 10% chance of that happening would be horrifying (in my opinion).
Example: Astronaut Tim goes on an EVA to perform an emergency repair after a micrometeorite damaged the space station. A malfunction of his space suit kills him. Everyone agrees that Tim died a hero doing a high-risk activity that needed to be done, and almost no one would say it means we can't do spacewalks or can't send astronauts to space anymore.
Compare to Challenger or Columbia: The whole crew dies randomly on the way up or down during a routine mission. A program which became known for having like, a 10% chance of that happening would be horrifying (in my opinion).