There is no one perfect but god. I don't like seeing people generalizing because they got a bad experience with [some] and not all of these people. If I got a bad experience with someone because he fooled me and I bought from him something with a high price and it costs nothing like that, should I feel angry at all of his people and assume that they are bad? If someone hits me by a car, should I also say that all of his race are bad like him?

Just don't let your anger blind your vision and even in that case, let your mind have the full control or you will completely lose it. Where there is bad, there is good also. You would never know about the bad people unless you meet the good people and vice versa. Don't think that you are perfect, very good and sinless. If you see yourself this way, then other people might be seeing you a bad person.

We are not angels, that is why the angels are angels and humans are humans. We are just trying our best to be good people in this life but we can't be in the end angels. We got our limit and that is why we are human. Before judging or creating any trouble for other people, know that there is god above you watching you. If you got the power to do that one day, then god have the power since the beginning of the creation of this world and would always have the power until the end of this world.