First of all, yes, private entities absolutely can ban you from speaking on their property. The 1A only restricts the government from jailing you. If we couldn't ban people from this sub, it would be an unreadable mess.
Second, the problem with the lefts cancelling is it was usually just a handful of terminally online freaks, digging through hundreds of tweets dating back years to find one example of a person saying "nigger", usually as a joke. It was completely devoid of nuance and purely vindictive.
The right is using it to get women who work with children fired because they're glad a normie was murdered. Does any normal person want a sociopath like that near thier kids?
The problem is always just the left, not the tools they use.
It’s already being used against us, and has been used against us for years, therefore I don’t care if it’s used against leftists. Although I do feel like we are being socially engineered to accept the death of the 1st amendment, I mean the total abolishment of the 1st amendment since they already chipped away at it years ago through the civil rights act, the fair housing act, and forced integration, which took away our freedom of association that’s supposed to be a part of the 1st amendment. Makes perfect sense for them to push people to give up on the 1st amendment if one of the main goals for the future is a government run social credit system that persecutes everyone for wrong think/speak.