It's stupid because it makes the assumption that your enemies are weaker than you, and will do what you want if you murder a few of them. But people aren't like that. I mean, think about how it will fall out. You go down that canyon and kill a bunch of people doing their jobs, and later other people come along and find the bodies. They'll hate you forever. Even if you do take over Mars someday they'll still hate you, and do anything they can to screw things up.