Can you please tell me

Why is it that people only speak to you when they need something from you in a office environment. Is it that I am not worthy of your greetings first thing in the morning. Is it that you are so totally consumed in your task at hand to acknowledge your fellow co-workers.

Or is that you are just a nasty, inconsiderate mofo, who is only interested in a person if you can use them for your task at hand. Just asking