I get that, and I think your post shows how one can steer a careful course between a destructive humility and overconfidence (let alone arrogance). Thanks for an excellent post — I’m gonna pass it on to my grad students.
But I think you misread Gina. As I understand her post, she’s not advocating saying one is a fraud to others. Rather she suggests responding to that inner voice telling you you’re a fraud with “yeah, right, because we’re all frauds.” Another meme that’s showing up in my twitter feed is “of course I don’t understand — as a software developer it’s my job to be working on stuff I don’t understand (yet).” My understanding of Gina’s point is that it’s ok to not be the great expert most of the time. And her “we’re all frauds” is a mnemonic for the ways that humility can contribute to problem-solving.
Sometimes you are the expert. Then it’s important to say “I’m no fraud, in fact I’m great.” I don’t see Gina denying that.