I wish we could just get rid of that particular form of "courtesy".

I can't help but be annoyed or distracted by naked hellos, regardless of the intent behind them, so to me, they are rude. I understand that they might be some sort of social ritual, but I can't for the life of me understand how it's in any way courteous to ask for someone's attention with an expectation of a synchronous reply before revealing anything about why they want your attention.

But I suppose the majority feels the opposite for some unfathomable reason.