I wanted to give my opinion on the matter of judgemental people/calling people judgemental, but now that I gave it some third thoughts, I feel more confused than before. On the one hand I've known people who looked at me with disdain when I did something my way, even if it really does not matter at all what I did. I remember being outside at a festival with some friends, and when I came back from taking a piss I felt insecure, and it made itself visible through my body language. A friend saw that and gave me a look that seemed to say "Pffff I see that you are insecure, and I am better than that". That was to me a moment in which I felt very judged for merely feeling the way I felt.
Now on the other hand, so much of what I took to be "real" in my life turned out to be a projection of my own inner psychological constellation, or mere projection, to give away some of the weight, or responsibility for my own inner state. So in retrospect it seems very clear to me that I projected some stuff of mine onto him, or/and that he was feeling equally insecure.
I think most people who seem to be judgemental, they do it out of an insecurity, anxiety, or the plain, old desire to be better than other people - the ego asserting itself to gain momentum. I know that, because when I was/am judgemental, it was/is exactly that mechanism. An enlargement of my personal identity at the expense of somebody else's, born of insecurity, feeling small.
There are also different forms of judgements. (I was about to write that nobody asks you not to use your judgement, but sometimes it seems to me that all of society is asking you to do that.) I think one can use judgement as a life-enhancing principle, or as a means of violence. I believe that the beginning of violence lies in putting labels on somebody, or just plain distorting reality from the existential fact. My flatmate may not have washed the dishes 3 times the last week, and I could say, "He never washes his dishes, that lazy asshat". Or I might say, "In the last week, he didn't wash the dishes 3 times, and that made me angry", which is way closer to the existantial fact than the first sentence, because the first sentence is labeling and categorizing the person, which reduces the totality of what this person is, making static what is actually totally alive and ever-changing, while the second does not reduce the person and leaves space for communication and empathy. If we did not reduce people to mere labels (enemy, bad etc., but good or neutral labels too) we'd have significantly less violence in our world. (let alone judgementality
(I stole the line of thought of the last paragraph from Marshall Rosenberg who wrote a terrific book about nonviolent communication, short NVC)
But well, using ones judgement to stay clear of certain people to protect myself is something different. To me it's quite hard to draw the line between self-protection is in a sane interest of wanting to survive healthily, or to protect my stubborn, childish illusiory self.