Even if the selection part is true, it chases away people who cannot be bothered to interact with a human being for 20 minutes or so. High value is a different set of people with unknown intersection.

No, it is not people who can't interact with a human being for 20 minutes, but with tens of them. If it were an agent / talent model, where it is a somewhat large amount of interaction with a single individual, that would be one thing. But interactively sharing the same information with 20 different recruiters is just a waste of time that has nothing to do with an inability to be bothered to interact with people.

When I get 10 LinkedIn messages a day, no, I cannot be bothered to interact with each of them for 20 minutes. And since they all refuse to send along any relevant details whatsoever, I can't even cull that to the subset that's plausibly interesting.