Every single American, no.  I did generalize, but as a culture, we most certainly accept killing others more than a lot of other countries.  Heck, arguably we're the single biggest killer on the planet with our wars...none of which are truly justified or doing what they're supposed to do.

Yesterday my son was watching CNN coverage of the church shooting.  A commercial played during it was one of those software war games that glorify American soldiers, with the soldiers killing a bunch of people.  We love that feeling.