Mormons teach each other not to judge. Dieter's recent Conference talk is proof.
The avalanche of "Stop it" memes that followed bore witness to the fact that Dieter had won the People's Choice Award for Best Conference Talk.
It's a good message. I think Jesus even said something similar. It's hard to argue with a good message that comes from Jesus. I'm just not sure Dieter captured the essence of Mormon judging. The judgment he's speaking of refers to "hating, gossiping, ignoring, ridiculing, holding grudges, or wanting to cause harm", there is so much more to Mormon judging than that.
In my experience, Mormon judgment is almost entirely concerned with righteousness and worthiness, and hides behind the façade of helping others. Because "judging" carries such a negative connotation, Mormons prefer to approach the issue in the key of "discernment". We have to discern between Good and Evil, and whether or not something is worthy or unworthy, or clean and unclean all the time. Worthy is good. Unworthy is bad, and sometimes evil. If we can't tell what's good, how will we know what's worthy of us? If we can't tell what's evil, how can we reasonably seek after good things? If we can't tell what's unclean, how will we stay clean before God? We have to discern who's worthy to participate in the sacred rites of baptism, sacrament, and temple work. We have to discern who stands in need of fellowship. We have a lot of discerning to do and that requires a lot of judging.
We're always looking for signs of doubt, weak faith, idleness in upholding the Gospel and magnifying callings, heresy, and apostasy. These signs show up everywhere and we have to be ever observant. It could be a can of Coke. It could be chronic tardiness to Sacrament Meeting. It could be a reluctance to bless the sacrament. It could be a colored shirt or facial hair. It could be failure to bring your own scriptures to church. It could be watching sports on Sunday. It could be a low cut dress or a questionably short skirt. It could be wearing flip flops to church. It could be reluctance to accept a calling or speak in sacrament. It could be a bumper sticker endorsing a Democrat. It could be poorly behaved children or children who's hair has not been tidied up. It could be a mild swear word. It could be the slightest disagreement with something that was said in General Conference. It could be the mentioning of an inappropriate movie. It could be a slanderous remark against the Founding Fathers. It could be a look of boredom in class. It could be not singing along with the hymns. It could be never raising your hand in Sunday School. It could be an uncorrelated comment in class. It could be your gait and composure. It could be your lack of a smile. It could be your avoidance of someone in the ward, especially authority figures. It could be so many different things, so we exercise vigilance along with our discernment.
Just know that we can and will discern you. Be sure of that. We'll scrutinize your every word and your every move. We'll figure you out. We'll categorize you flawlessly. We'll put you in your place.