Remember that interpersonal disconnect I mentioned to you before elsewhere? Most of us care about other people because we are able to bond with them, to relate to them and to care for them - even if we have not even met them. This is "empathy" and it leads us to care about what happens to them. "Altruism" motivates us to discuss wrongs done to others and to try to figure out ways to lesson or eliminate those.
When we find that the people we have elected to care for all of us (the government) have not only let us down in that, but have chosen to kill us, our brothers and sisters, our fellow citizens, without either good cause or due process under law (as explicitly detailed in our federal constitution), we get concerned that they may well do this again and some more. Thus our concern.
I recall that you do not quite understand this aspect of human behavior, but rest assured that most others amongst us here do. While you may not share these simple sentiments, rationally it behooves you to consider that many of the rest of us do and it is important to us. I hope that this helps you to understand why we are so concerned about our government killing us - if they did it a couple of times, how are we to assure that they will not do so again?