it is so blatant and looney that “unconscious bias” cannot possibly apply

You consider it blatant because you, me and most people reading this live in a bubble of awareness. I assure you these things happen every day in many organisations, especially in the tech industry, and the people doing it are oblivious.

Not that that is an excuse. Being oblivious means those managers are incompetent, and especially tech has a many decades old problem with incompetent, oblivious management.

In that respect, the diversity issue is just one of many issues making the tech industry a relatively toxic environment. Or rather, it’s one of the root causes of why tech has such a deep and intransigent diversity issue.