Let's ask this another way: why aren't business men considering the ethical implications of their investments? Why aren't militaries, bureaucracies, and governments considering the ethical implications of their orders? Why isn't the average person taking five minutes to understand a problem now so he doesn't demand government, the market, and God on high give him an answer that he's going to hate more than the original problem a year from now?
TFA presumes that we as engineers are smarter, better humans than everyone else, that we can and should forsee all of the ethical implications of our work. It's pure hubris, and I call shenanigans. By and large, engineers do what their employers pay them to do, to feed themselves and their families. IMO, every link in the chain should be held to the same standard of moral accountability. We're not exempt, but it's unreasonable to expect us to take any more (or less) responsibility for the bad things that our work makes possible.
That said, I once quit a job working on systems that could be used for what I perceived as evil. My girlfriend (also an engineer) works for a military contractor, and I give her a hard time about that occasionally. Her response is that she works on detection systems, not weapons. To my mind, it's at least a waste of good engineers to further meaningless political power struggles, and keeps the warmongers in business.