who is responsible for the deaths documented in the book? Ultimately, is a person responsible for others? Is self-preservation the bottom line here?

Although some people might be more accountable than others, I think Krakauer ultimately holds greed responsible for the disaster on the mountain. Nepal would let anyone climb for the right price and experienced guides, who should know better, led inexperienced climbers up the mountain for the right price. People paying big money to summit the mountain put a lot of pressure on the guides to make their investment deliver. Unfortunately, the mountain is unconcerned about human greed and frailty.