Perhaps, but that's still not something we consider state action. People lose their jobs or reputation all the time, and we don't consider it worthy of redress.
Many people appreciate the American right to refuse service to anyone; this is that same impulse exercised towards racists and bigots.
Time heals most wounds. Although it may feel like their reputation was "completely destroyed", I think many will find that they can get another job, once the immediate thunder and fury blows over.
Gee why does crime happen when we have laws against it!?
Good luck suing a Twitter mob or some activist/student who has no assets but can crowdfund a legal defense fund overnight which they won't need because there will be a line of lawyers wanting to represent them pro bono.
Also riling up a smear campaign does not necessarily rise to the level of defamation. You can get fired for simply having the wrong opinions. I'm sure you have no trouble seeing this as a problem when it's the people you like suffering that. Headline: BLM activist fired from their job for saying woke shit. Much outrage. Oh wait they just need a defamation suit. All good then. Right.
Yes, it happens. It's the nature of an employer / employee relationship; being a BLM activist isn't a protected class, and in only a few states does he have any legal recourse (in California, there's a law against firing a person for political affiliation). We definitely have a system where political activism is something those who have plenty to defend themselves or nothing to lose are best suited to engage in. I wouldn't have recommended to him he do this if he couldn't afford to lose his job.
I think you may have lost the thread though... I was talking about false accusations. Defamation would not help in a case like this one, as truth is always an affirmative defense.
The other point you raise (crowdsourced harassment) is trickier. IIUC, you could sue someone with deep pockets for that... "I heard what I was saying from someone else" is not a defamation defense. But a lot of the mob is bankrupt judgement-proof types.
Defamation isn't the worst of it. There's an ocean of normalcy between wokeness and alt-right, people forget that. It's ok to have different opinions on equity vs equality, on social norms, etc. You're not a racist bigot for not supporting every woke cause, despite what they claim. Yet having the wrong opinions will easily get you fired if you cross some woke activist on twitter or at your workplace / university. This isn't something a lawsuit or a thousand lawsuits can fix. It's the new repressive culture we're heading towards.
I think it's more the same repressive culture we've always been in, but new centers of power have emerged in it. Different people, as a result, are now feeling what was always there.
You could always be fired for doing something embarrassing to your boss (witness the example of the BLM protester who worked at a library and shared a book-burning video). But the "woke" now have enough social / economic clout to cause a big enough stir to shift the window on what's embarrassing to a boss. Whereas in the past, for example, inappropriate activity with a subordinate was swept under the rug "for the good of the corporation" (but having the wrong hairstyle could get you fired), now enough people agree such rug-sweeping shall no longer be tolerated (while hairstyle standards were probably racist) and corporations have reacted to new incentives.
Many people appreciate the American right to refuse service to anyone; this is that same impulse exercised towards racists and bigots.
Time heals most wounds. Although it may feel like their reputation was "completely destroyed", I think many will find that they can get another job, once the immediate thunder and fury blows over.