Normally, when someone engages in behavior seen as offensive, the procedure is to pressure the person to apologize and mend his ways, and only get rid of him if he refuses to do so.
But when a "scarlet letter" offence is involved, we jump straight to the punishment phase, removing the person outright with no judicial process. This is completely backwards, anti-democratic, and anti-freedom. It brings a chilling effect on everyone, because suddenly people start to realize that they're living under the Sword of Damocles, which could destroy them at any moment without warning. You can never be sure if something you say or do is going to get you publicly pilloried in future, and destroy your career, friendships, and reputation in the blink of an eye. Far better to just sit quiet and never say anything that might offend someone. Far better not to participate at all.
Mob justice always turns ugly in the end. That's why we have courts.