The Torah teaches us that we should be dan l’kaf zechus because Hashem knows that as human beings, we automatically make judgments all the time. Imagine a world without judgments, where we could not discern whether a street is too busy to cross or if we would like to marry the person we are dating. Judgments and the ability to discern are necessary for our survival. It is vital, however, to note that judgments, rather than describing the facts of a situation, often spike emotions and distort reality. Therefore, when we approach mindfulness, we do it with an attitude of nonjudgmental-ness.
Judgments are really any beliefs or interpretation of an observation rather than what is being observed itself. In mindfulness, all judgment is avoided because we are focusing on what is, not on opinions of what is, regardless of whether they are positive or negative. In mindfulness, we attempt to avoid judgments completely because they are not actually helpful. Think of judgments as emotion amplifiers; whatever we feel, including pain, is amplified by any accompanying judgments. Judgments are also not helpful because they are not descriptive, they do not give us much information.
Let’s take a moment to differentiate between judgments and evaluations. Evaluating whether something is dangerous or unsafe, A+ or C- work, or fresh or rotten, is actually quite helpful, and likely the reason we are so good at judging in the first place. It would be helpful to be able to discern if there is water in a pool before I jump in. Evaluations help us, but judgments tell us what is good and bad, which is unhelpful. It can be anything from “this mindfulness stuff is silly” to “that practice was amazing” to “I noticed that picture was taken at an awkward angle.”
Sticking with the facts, such as “I feel silly and awkward when we practice mindfulness” or “I enjoyed doing that practice” or “I noticed that picture was taken from the side” can help us avoid judgments and avoid escalating emotions based on interpretations of reality. We aim to describe only what we can observe, only the facts, leaving the interpretations of what we observe to Hashem.