For most of my career (I'm 48 now), I have loved my work. But the last 10 years have been really revealing in a bad way. I don't want to build information weapons, and that's how I'm starting to feel all the time.
For me it ultimately boils down to my personal morals . I am not comfortable supporting these types of companies, even if my contribution makes minimal difference (on either side). I refuse to contribute because I wouldn't be comfortable with _myself_. I hope this decision will be beneficial to more than just myself, but if it isn't I'll at least be happy knowing I did what I could to support what I believe in.
(side note, I didn't mean this to be so subjectively idealistic, but even if you completely disagree with my opinion on tech, I think the introspection and focus of attention would benefit all)