Well, I'm sure nobody's ever walked up to oceanghost and said, "I'm not hiring you because you're an old(er) white male" (although, unlike every other possible form of discrimination, that would be perfectly legal), he just probably has a sense that this is what's going on based on the attitudes around him. But I doubt that the author of the linked article has ever had anybody come up to her and say "I'm not hiring you/promoting you/supporting you because you're a woman (or 'of color')", either - if they had, I suspect it would have worked it's way into her article somewhere. Instead, she just gauges the attitudes of the people around her and makes her best guess as to why things aren't working out the way she wants them to. If her suppositions are reasonable, then oceanghost's are, too.