The way to say hello

Americans have a way to make the simple procedure of acknowledging that you are to something unbearable and wrong for me. Usually when you meet someone at work for example you say hi to show that this person is important and that you see him or her. Sometimes you might add a "how are you today?" Where I come from we then stop to hear the answer to such a question since we actually asked. Failing to do so would be considered shallow and cold. It is not in any way unheard of but I guess it was along time ago that I choose not to keep those persons as friends. A natural selection of friends if you will. But in this country nothing is strange with a conversation sounding like this:
Person A walking briskly through the corridor noticing person B who might or might not be named Marcus, but probably has a name that starts with an M.
Person A, opens his mouth without stopping or even lowering his pace and says: -"Marcus, what up man?"
Person B looks towards the passing Person A and answers: -"Yeah and you?"
At this point Person A has moved far enough away in the corridor that he no longer can or need to answer the question posed by the person presumably named something beginning with the letter M.

For me this tears a hole in my soul. I usually only say hi, but if someone ask me something I always think about the question long enough to give it an answer. The answer I feel it deserves since another person, a human being asked me the question. This upsets every American. I can't start striking up conversations with people whose names I hardly know the first letter in. But still I both answer questions to my health and well being and pose other questions back to which I seem to be expecting answers. This is out of protocol. Just a trivial thing like answering truthfully about your problems and feelings can be severely chocking. This is the same in Sweden but to a lesser extent.

I'm just saying: if you do not want the answer: do not pose the question.