Often we tend to understand people our way, we don’t even try to understand their perspective. We mostly never treat them the way they are, we treat them as we think they are. Only constant communication will allow you to understand them better.
Also, everyone has a basic nature, some open up the moment they meet people, some take their time to open up and understand the other person before putting themselves out there. On the other hand, some are plain introverts they would only communicate when someone puts an effort to communicate; otherwise, they are okay being by themselves.
People are different and not everyone would get along with everyone, you tend to have your comfort level with some of them, and with some, you only wish to keep it short. There may be no wrong in being that way.
Sometimes you may encounter instances in life where you are forced to communicate with people you do not like to communicate with, however in this case most of them generally try to break the ice just so they try to keep the communication on and manage the person just the way they are.
A major example of this is a joint family, people living in joint families may not necessarily get along with each other but they tend to find a midway where everyone stays happy. It is practically not possible for a person to get along with everybody, however, one can just accept people at the face value. This not only makes it easy for the relationship to sustain but keeps the unwanted friction at bay.
In wanting people to understand us more we fail to understand them better, I think the first step towards having an expectation from someone is fulfilling an expectation, which means if I expect something from someone, there might be a possibility of someone else expecting the same out of me.
So treat everyone the way you want to be treated.