I understand the point of this is efficiency, though I feel it's necessary to give voice to the other persuasion: are we really going to pursue maximum efficiency in trivial matters to the point that it no longer sounds like it's human beings communicating?

There are such things as rudeness, crudity, boorishness--and in my opinion, those don't go out the window in the workplace. Keeping your interactions civil and pleasant is important, just like getting to the point can be important too. Saying "hello" before asking someone a question is polite because you're treating them like a human being, not some question-answer bot. Being too aggressive in eliminating these "pointless" social signals can have a cumulative effect of making you look like a real jerk that only values people for their utility in a given situation, in other terms, treats others like objects.

I shall remain a staunch defender of manners and etiquette and pepper all of my conversations with so-called needless pleasantries.

All that said, I of course don't promote saying only hello and then waiting for a reply before proceeding. That's just silly.