Well, it depends on your point of view. Your question is a twist on the old "is the glass half empty or half full?" question. Virtually everything that has been created of a useful purpose was not created with a destructive end in mind. That is not to say some inventions had that as their very existence, to kill, to annihilate, to maim, and to destroy. Many of Hitlers advanced war weapons had to do with germ warfare, faster, more lethal machines designed to kill.
Take the lowly pencil, for example. In most schools, pencils are required tools of the trade. Schools now have a no-tolerance policy on weapons in schools. But on any given day, a sharp pencil would make an excellent stabbing weapon, capable of putting out an eye, or puncturing a lung or the heart. I remember the story of an elementary school kindergartner who was suspended from school because she had brought an ordinary, run-of-the-mill butter knife to cut her chicken she had brought to school for lunch. Often-times, we over-react and throw the baby out with the bath water.
So should we stop inventing because someone uses our inventions for things we did not intend? I say no; if we did, we would still be living in caves, stuck forever in some stage of preintelligent development, afraid to push the envelope for fear someone might use it for evil instead of good.