Because they are just not any of those things.
There is no way to understand people until we understand that we are not purely logical creatures. Our emotions make it so we can never be such.
Probably one of the stupidest attitudes one can have in life is to assume that people are logical and sensible. They’re just not. People are irrational. If you think people are or should be rational, you will be disappointed and angry at other people your whole life. You will see others are idiotic, crazy, senseless, etc.
But once you figure out that our emotions color our thoughts and actions and there is an “emotional logic” behind a lot of behaviors, you can start forgiving people a lot more and your feelings about your fellow humans will mellow and become more kind. Furthermore, a lot of behavior you thought was crazy now makes sense if we plug it into “emotional logic.”