People who commit such acts do not see that there is a solution to the problem at hand other than death. In individual cases, this can be seen as unethical, not in just the way it affects others around them, but also they are not giving themselves the chance to grow spiritually through working it out.
Ethics have evolved so we can live together peacefully and not be in fear that we will be attacked or be stolen from, at least in our immediate society. We trust that others around us hold similar ethics and therefore we are outraged when people break the ethical code and commit crimes.
Yet ethics can change according to the situation or culture we were brought up in, honor killings may be seen as perfectly ethical by some cultures. Mistreatment of animals is seen as OK by others. People who do not value life, whether human or animal, cannot value their own lives either.
It all comes down to how do you honor the life within yourself. Ethics starts with being good to yourself and cherishing your own life. From this comes the Golden Rule, which is the most basic ethical principle on this planet:
“Do unto others, as you would have them do unto you.”