In Buddhism, compassion is practiced more because, every person you deal with is someone you either have been, or someone you will eventually see in yourself. So there's no point to criticize because you always work towards mutual understanding and compassion.
You don't have to practice the inward neurotic obsession of identifying flaws or the external compulsion of alleviating the burden of knowing yourself - because you'll focus on them when you do. Every person you meet knows you and every person you know is you.
I don't consider myself a Buddhist but I've always aligned myself behind that way of thinking. Even in a non-spiritual context, most people have similar struggles in common: nobody asked to be put on this planet, everyone was torn from the safety and comfort of the womb to be thrown into a chaotic world, we're all just trying to get by providing for ourselves and our loved ones, and we're all trying to enjoy life while we have it.
It would seem obvious that when you hurt someone, you are merely hurting a different version of yourself, a version simply displaced in time and space and sitting in another man's shoes.
I think some people at some points in their life think that it's okay to judge others, because they think they will never be what they judge.
But we always are that, generally, we experience those emotions eventually, in some shape or form. We judge we get judged. Til the end of time, eventually we die, we are alone, with only our thoughts, and a question of what we will become next. And all we have is everything we have ever known and thought, on a deathbed. And all we have ever known and thought are, how we know ourselves and how we know others.
And all of that is in the mind, at the moment of death.
So I think while living, it's important to let go of whatever causes the cycle of wanting to judge and wanting to hurt, people hurt when they feel hurt.
When we feel judged, we judge. But generally, we can never really know if we are being judged or hurt. Because life is an experience, of coming and going, of interacting with a self we think we are not, but we are.
Zen koans can be good to think about (to me), when one dwells too much on what a self means, when one has to interact with other selves in real life. People need a sense of self, because sometimes we are with other selves, sometimes we are with our self.
You don't have to practice the inward neurotic obsession of identifying flaws or the external compulsion of alleviating the burden of knowing yourself - because you'll focus on them when you do. Every person you meet knows you and every person you know is you.