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.
Yes, absolutely. Man has invented many destructive things, from guns to nuclear bombs to addictive drugs like methamphetamine. Many of mankinds' great inventions may lead to self-destruction, because these inventions, while increasing the comfort and improving the lifestyle of individual people, are simultaneously overstressing the planet's natural systems, which could conceivably lead to environmental collapse and the destruction of human society.
One key consideration is to think about how the invention is used. Inventions themselves are morally neutral; it's the way people employ them that makes them good or bad. Additionally, we must consider balancing the good of the individual with that of the human race as a whole. If an invention improves one life, but makes that of several other people worse, is it a good invention? It depends on who you ask.
I completely agree, man has created various very uselful and advanced pieces of technology and machines which make our lives much more efficient and easier, however on the other hand, man has also created vast amounts of 'instruments' capable of massive destruction and damage.
To illustrate that we can look at the simple example of the nuclear bomb - considered an asset capable of causing mass killings and famine lasting centuries. Perfect example would be the nuclear bombs dropped by the Americans at the End of World War II in Hiroshima and Nagasaki in Japan - the aftermath effects of the bombarding still exist and will exist fir another 50 years...