This is because the US is not one homogenous system of thought, but rather a mosaic of people with differing views. (This goes for any other country or population for that matter.)
A more constructive observation would be to consider the overlap in groups of people who (1) hold that murder is indefensible in any case, and (2) hold that death sentences are appropriate for crimes. While not sharing that view myself, I could think of a few factors that may lead others to espouse it, such as:
- an implicit trust in authority and deterrents (follow rule, "or else");
- feeling of being mostly immune to errors in the justice system ("this would never happen to me");
- a propensity to desire revenge but only when it pertains to "others" ("I'm a good person, we must punish the bad people")...
A more constructive observation would be to consider the overlap in groups of people who (1) hold that murder is indefensible in any case, and (2) hold that death sentences are appropriate for crimes. While not sharing that view myself, I could think of a few factors that may lead others to espouse it, such as:
- an implicit trust in authority and deterrents (follow rule, "or else");
- feeling of being mostly immune to errors in the justice system ("this would never happen to me");
- a propensity to desire revenge but only when it pertains to "others" ("I'm a good person, we must punish the bad people")...