If everyone's excuse for doing evil things is "it's just a job," "not my department," or "above my pay grade," then those evil things will continue. Everyone is responsible to make an ethical decision with regard to the jobs they will accept, and the assertion from the HN posters to which you refer appears to be that those taking a TSA job have made a questionable ethical decision in doing so.
As for why it's on HN, many here have dealt with being treated like an outsider or an inferior, and have a heightened awareness of such issues. There's a long tradition of geeks taking up non-geek causes because they would want the same (that is, non-geeks taking up geek causes).
As for why it's on HN, many here have dealt with being treated like an outsider or an inferior, and have a heightened awareness of such issues. There's a long tradition of geeks taking up non-geek causes because they would want the same (that is, non-geeks taking up geek causes).