Sometimes people use political correctness and right concepts or idea in order to satisfy their own egotistic, domineering and self righteous attributes. A bit like a boss or a teach who abuse their power.
It is wrong for people who use your others wrong doing as an excuse to bully them or vent their anger on the wrong doer.Sometimes when someone is in a wrong, as long as you admit your wrong and change then that is sufficient, and extra bullying is unnecessary.
There are people who face psychologically damages unnecessarily because of the mental abuse afflicted by their mistakes which isn't justifiable. For instance, some people maybe bullied and branded useless and pathetic in general for their poor work performance in computer programming, and feel like a useless and pathetic human, which is not true. They may have other good skills such as in science, literature, mathematics, business skills or have great character but just happen to perform poorly in one aspect... It is important to separate being a failure as a person and in a specific skills.
And as a famous quote goes: "Strong people don't put others down... They lift them up"