It seems to be a bad part of human nature that we want to judge other people's behavior, looks, actions, possessions, beliefs, etc. Perhaps we all feel a little insecure about ourselves, and so by looking down on other in areas that we feel they fall short, it gives us some reassurance. Some people have a terrible habit of talking about others, but nearly all of us are guilty of at least going through the mental exercise of judging others. The main reason that we should give others a break and not judge them is that sooner or later we will probably do what we condemn them for. Things just work out that way.
Life is sometimes like a two-way mirror.
We don't even realize we are being watched. None of us would want to be judged by the standards we hold others to.