I understand the need for people to have jobs. I'm not unhappy about individual soldiers, individual cops, individual TSA workers deciding that's how they want to get employment. (I'm sort of unhappy at society-as-a-whole for making the military such a good career decision for many people, but the fact remains that it is a good career decision, and I won't begrudge that.) I'm not unhappy about you, because I have no idea what your job is or what your life is like. But this article is about a person who had an extremely good job at Google deciding that he wasn't doing enough for the world and that he could make the world a better place by working for the DoD. He could have stayed at Google; he could have even worked for the USDS for any of the non-war functions of government, if he really wanted to. I think that's fair to criticize.
However, even in "peaceful" countries you'd have a hard time avoiding that, as most of them have some sort of mandatory pensions system, who in turn most likely fund arms production, which will then sometimes be sold to be used for war.
So the same logic would be okay with people where all reasonable career decisions require working for a company that pays taxes to the military, and both Matt Cutts and I seem to be in that situation. But I think we're both in the situation where we have plenty of reasonable options other than working for the military directly. And it specifically sounds like he took an option that is worse for him personally, because he thinks it's better for the world. I disagree it's better for the world, simple as that.
(Whether this logic would forbid working for companies that support the military indirectly is an interesting question, and I think 'BinaryIdiot has convinced me that it should.)
I get it. You hate war. Most people hate war, even the soldiers in our army hate it. You want change? Vote and get outside and protest. Don't shit on a DoD contractor while sitting there doing nothing.
Real change requires real effort.