alt Hacker News> if enough tech workers at Microsoft felt strongly about these ethical issues, they could influence Microsoft's decisions internally
This isn't how companies work or are structured. If you have the CEO's ear, potentially. If you don't, the only ethical thing to do is to quit. (I don't personally have an issue with the military per se. I have other issues with several tech companies which would make taking a job there something I couldn't do.)
If something bad is going on and you don't agree and you quit, that is just absolving you of your guilt. I mean think two steps ahead. Is M$ going to go "gee, Jimbo quit, maybe the project is just no good and we ought to stop." Hell no. They will fill your position with someone who will be thankful for the opportunity. And I think ultimately you know it, but a bit of cognitive dissonance makes you think you did something.
Why are so many people supposedly principled but not militant about it? A principled militant would use their role in m$ as an opportunity to be an anchor to the efficiency of the operation that they do not agree with. They will fight to keep their position such that a more effective less moral person might not take it over and get the project moving.
One has to wonder how many projects in the world are in such a holding pattern, protected by people who had the foresight to think two steps ahead, attempting to keep their body holding that door shut as they possibly can.