Just like oil and water don’t mix, some people don’t mix. Some people could be perfectly fine by themselves or with their family, friends, and people with similar interests and values as theirs. They could live peacefully and productively, just as oil and water each can be mixed with similar ingredients as themselves. But, mixing oil and water together won’t work. You can try as hard as you can to combine them, they will not mix well.
It’s the same for some people. If you mix them with people they disagree with or don’t understand, if they are not willing or able to be open-minded and empathetic, they will not get along … no matter how hard you try. Any efforts to force them to get along will not end well.