Why do people assign such value to life, when it's really just a matter of chance and biology?

It’s something I haven’t understood for a long time, why people get so emotionally-involved when you start talking about life and death. I personally don’t feel that life has any inherent value, but that it’s simply a matter of chance, biology, and personal connotation (i.e. that we as individuals would miss someone or something were they to not exist).

The only magic I see in life is the brief distance between life and death (i.e. someone/something existing and then suddenly being gone), but I do not feel there is anything magical about life itself.