It's simply nonsensical to think that there are two extremes of discourse, "echo chamber" and "people can feel free to voice threats," which are in opposition.
> It is a big deal only if Garry was consistently inflammatory. Otherwise, it can be safely relegated to careless jibe by a drunkard.
People on the business end of a threat certainly have a different perspective on what can be "safely relegated" to the "don't worry" category. There's nothing wrong with taking into account the perspective of those being threatened when determining whether something like this is a "big deal," as the parent poster presumably did, and as the law does.
> It isn't normal for anyone else, of course. As for Garry, he is heavily invested in SF politics.
How unique he is. It's hard to imagine a reality where lots of people are heavily invested in politics and behave foolishly because of it. That would be an alternate reality that is difficult to imagine.