This argument comes up over and over in this debate, and it seems like the result of some misunderstanding. You’re certainly allowed to react in a way that’s punitive as long as it’s a legal action, you won’t be violating the law, and I don’t think anyone claims otherwise, but you’ll be violating the cultural norms of free speech by engaging in repression. If you generally believe in the freedom of speech as a principle, you believe that people who you disagree with should be able to say their piece, without your feeling the need to retaliate, because you know that that’s what’s necessary to maintain a culture of free speech and open, honest discourse. But when you try to punish or retaliate for someone airing a view you disagree with, you’re going past civil discourse into actions intended to harm them financially, emotionally, or otherwise. And that’s frankly harmful to democracy.
If they say they hate your family directly to you, sure, don’t eat there. But most speech that people disagree with and try to retaliate against the speaker isn’t on that level - it’s bits of speech taken out of context, indirect expressions of opinion like donations to candidates, etc. People are being manipulated by professional propagandists, and they’re following along enthusiastically. It’s polarizing the country, and it’s actively harmful to the stability of the democracy.