On Common "Courtesy"

In life, throughout the course of time, most people will make a large number of acquaintances. Some of these acquaintances become friends. But the percentage that acquire this status is very small. People that are known from the neighborhood, through relatives, or by some other means pop up in everyday life from time to time.
When walking down the street, it would obviously be rude to completely ignore someone that you know. The encounter should certainly be acknowledged with some form of salutation. But my complaint is not with those who pretend not to see me. My issue lies with those on the opposite end of the spectrum.
Too many people, that are considered mere acquaintances, feel the need to stop me in my tracks to ask a series of asinine questions. The questions almost never vary, and remain constant even when asked by different people. The typical questions are as follows: "How are you doing?" "Are you still working at the same place?" "How is you mother doing?" "How is your brother/sister?" "Where are you off to?" "Send my regards." Then I have to stand there in this recurring event answering "Fine, yes, fine, fine, somewhere." It's like deja vu all over again. Of course the person can sometimes throw you for a loop by asking "Did you hear about so and so?" But the precise questions aren't the issue. The issue is that this person is asking questions that he or she already knows the answers to or questions in which the answers are irrelevant.
Why do they do this? The typical answer seems to be that such a prescribed series of questions is known as common courtesy. But is that really being courteous? Courtesy is supposed to be a polite or generous gesture. Is it now considered polite to delay people for no reason at all? Is it generous of them to bestow upon me a bunch of useless questions? I think not. I would much rather hear them say "Hi Gary." Then I can say "hi" back without stopping. Both of us would still gain the same mutual acknowledgement without the unnecessary interrogation.
So if you see me walking down the street and truly have nothing to say to me, say "Hello." There is no need to run down a list of each family member in turn to ask how they are. I will tell you now, they are all fine! If you have something interesting to say, you may stop me-- I am more than willing to listen. But if nothing is new, and the questions are monotonous, just leave me be. Say "hi" and let me move on. I really can't be bothered.