I think you (and some other commenters here) are making the mistake of saying that because we cannot predict the future perfectly, that we are absolved of any responsibility for thinking about negative outcomes.

> programmers should not try to determine how society will react to technology

That is exactly one of the most important parts of our job.

Do you think doctors should not think about the wider impact of treatment decisions? Legislators should not think about the second-order effects of the laws they pass?

Yes, prediction is difficult (especially about the future, as Yogi Berra said). We all know this. Most of the things that most programmers are doing have known and predictable effects, because most of what we are doing is not new. If we had no idea how society would react to technology, why would we even develop it? Of course thinking about the effect that your work has on the world is a basic responsibility of any human being, how it could possibly be otherwise?