This reminds me of the sci-fi aphorism that any space drive powerful enough to be interesting doubles as a weapon of mass destruction. Similarly, so is anything powerful enough to deflect an asteroid which is a danger to the Earth.
So it's technically true, but do you really want to live in a world where we will never explore space or pursue technology that could one day save the species because we're afraid of what the worst of us might do with it? Sounds awfully depressing to me. Might as well consign the rest of humanity to grubbing plants out of the earth for all eternity. I'd prefer to see us blow ourselves to bits with some crazy futuristic technology than have no hope for our future besides running around in fields until the expanding Sun destroys the planet, which we'd have no hope of being able to deal with.