> The only counterpoint here is, I think, that the severity of such punishments seems to be vastly underestimated.

I suppose I disagree: Modern forms of this ("cancelling") are well-aware of the economic impact it can have on individuals, and indeed often this is the intended outcome. People on all sides of the political spectrum here understand the impact of impoverishment and homelessness (though they obviously disagree on what should be done about it).

> The question is not whether we should shun people (we should, with a fair few qualifications), but whether such penalties should be levied for words

I don't see how you ever disentangle these two. For a large part of the populace, there are some combinations of words they will find abhorrent and want to punish. The exact nature of that punishment is up for debate, but we've largely settled on the status quo here.

If you can find some way to keep people from wanting to punish some subset of words universally then congratulations, a few nobel prizes are indeed yours.