To cancel or not to cancel, that is the obsession

I have an honest question with a hypothetical; I'm not saying this applies to anyone in particular. Suppose someone spouts outright racist or hateful speech, like "that race should be exterminated." And others go on a campaign to boycott him and it costs him part of his income. Who is ultimately responsible for that loss of income?

Granted other cases are not so cut and dried, but what about the free speech of those calling to cancel someone for their comments? Just asking for that boycott doesn't force anyone to take it up. Those asking for it have to make a case for it and let people decide to join it or not. E.g., when fisherman trapped dolphins in their nets and people boycotted those companies and forced them to have dolphin-safe products and the government to enact laws to protect dolphins.

I'm also thinking of the specific case of BDS against Israel. And how the US government is canceling that free choice to join the boycott by punishing those businesses who participate. That's different from allowing those businesses to make a free choice like above. And it's main motivation it seems is the money our government gets from Israel rather than some righteous principle.