It's great to remember that everyone only sees their preconceptions of people, but it's impractical not to judge people at all. Without judgments, there's no basis for interaction. Without judgments, people wouldn't be able to have intuition on whether to trust a business transaction. There's no way to have enough concrete proof in every transaction to conduct business without some level of trust. How does one know whether someone is trustworthy? It's a judgment call. There's a fine balance between being rigid in preconceptions of people and not judging people at all, even with being mindful that it's all happening. Since all of this is happening in real time, there's bound to be fallibility in the system. Knowing that no one can see every complexity of a person doesn't change much of human interaction because keeping that in mind to the maximum level possible would make human interaction very difficult to conduct.