As a Greek person I love it when people use our ordinary words as fancy words!

Not sure if the point you're trying to make. The parent called it a "cultural thing unique Silicon Valley", which to me implied that it's pervasive in people's thinking. But it's not. The fact that some few CEOs seem to think that way does not make it a "cultural thing" by any stretch of the imagination. It's a scheme to make money and gain market share, not commentary on social values.

That the interest in a single unified online identity is not merely exceptional in its association with Silicon Valley, but a specific subset of the Valley: power-brokers and corporate heads.

There are of course exceptions -- rank-and-file tech workers who have drunk the cool aid, and some outside tech who think this is a Good Thing (often for Others but not Themselves).

Ascribing the fixation to SV is, again, generally accurate.