In my humble opinion, it boils down to many things.
First understanding what causes people to be judgemental in the first place. I like to think it mostly stems from conditioning, bitterness, brainwashing, egos, or unfairly reminded as someone else (stereo-typing). Sometimes a combination of them all. No one is BORN judgemental. That's silly lol. Personally, I never judge anyone on first glance but... I do, out of behavior. I'm honestly, more on first impressions than I'd like to be. I read a lot of people out of self defense and empathy. I still bounce around and never take my initials thoughts permanently but the seed is planted at that point. If you rub me off the wrong way or give me bad vibes, then it starts to manifest. The anger or dislike will start turning the cynicism in me. That's where, I sadly, judge.
It's also about bias. I'm sure some people stopping judging someone once they've grown to like them. No different than someone who is incapable of seeing the bad in anyone they've become infatuated with or falling for.
To imply that everyone is judgemental is no different than saying everyone is bitter or cynical. Which is not the case imo.
Want to not be judged by friends? You simply have to find accepting friends that aren't the judging type, or are entirely like you where they honestly can't unless it's hypocritical lol. Constructive criticism sure, judging, no.
Seeing how someone talks to you about your fellow friends is a strong indicator if they are the judging type. The toxicity of your circle, if you will. Some people live for the drama, others avoid it.
Find the friends you can be, YOU, around. Don't let anyone potentially egocentric and full of THEIR life 'experience', tell you, it's never attainable. That's their life lesson, not yours. Experience and/or projecting more times than not, sadly turns people into self justified and righteously bitter hypocrites lol. God knows it's not easy, but at least try to be the better person to end the cycle.
I sometimes fall through the cracks myself but my motto is, If you're incapable of looking at yourself and trying to heal yourself (holding on tight to your current self), don't even try to heal others. You're teaching the wrong lessons from a bad place.
Sorry for my over explanations lol. In a nutshell, I believe "judging" to simply be defense out of conditioning or an emotionally driven thought from the more hateful side of the spectrum. Laced from another emotion or bad experience (told/taught or experienced first-hand).