I've personally been disqualified because I've worked at a legal, but "vice" based company - I've seen others not hired because their previous company was too "legacy", even though they did very similar work.
It's not necessarily right, but companies use the signals available for them - even if they're not 100% agreeable to everyone.
At that point, I was conducting dozens of interviews a year, and I think that sort of question came up... maybe three times? One of those people was from a medical company with a very large and very embarrassing contemporary incident, and the interviewee and I talked about development process problems. In fact, they admitted, it was part of the reason they left! We hired them and I enjoyed working with him.
And fine, but then when that horrible thing makes the news and their answer is "i don't care, i was just building the feature", I take that to be an extremely unsatisfactory answer.
And if they work at Facebook with those kind of unsatisfactory answers, they are probably very qualified for a lot of positions, and I don't think they'll be hurting for job offers elsewhere.