I don't hold it against people for only caring about one or two issues. In addition to many plausible explanations, people like OP who take a stand are already doing so much.

I for sure agree about encouraging people to dig deeper and wider, and that absolutely none of this is new or is occurring in a vacuum, but (and I don't say this to single you out, this is just a long-held feeling I've had) I do also think it's important to encourage and commend anyone who reaches these conclusions, however late or nascent they might be. Especially someone with the backbone to speak out at and then quit a cushy, prestigious job.

Something something every journey, something something single step. For the author (and for all of us, really) I hope it's one of many. And I think they should be proud of this particular step :)

The main answer would probably be: because he worked for Google Deep Mind as opposed to Google in general, so the killerbot and mass profiling concerns were immediately relevant to him and his work.

Your comment seems to be whataboutism. The article was not an essay trying to prove that he knows the secret to being maximally effective at politics, or whatever it seems you were expecting?