I think the problem here is inherently that the Stack Overflow model of community moderation doesn’t necessarily scale to highly specialized sites.
The idea behind community moderation is great: it’s an ultimate form of democracy and it lets the community shape itself without outside influence, and will invariably reflect the majority opinion.
But this only works if the community is robust. And this means large, and knowledgeable to some degree. For some Stack Exchange sites, this isn’t the case and English.SE is a prime example. Most users on this site are probably dedicated enthusiasts (like myself), not professional linguists, and there aren’t too many users to boot.
Furthermore, the site is essentially open to everyone. Again, this is usually a good thing. But it also means that the decisions about the community are no longer made by the informed only, they are also influenced by ignorants (and I don’t mean this pejoratively).
This is what has happened here. And I agree with Jeff that this is just the way the community platform works.
But it shows that this open community doesn’t work in each setting. If a professional community is small enough that it can easily be overrun by disinterested outsiders who just want to cause disruption, precautions have to be taken, otherwise the discourse will be disrupted. Imagine if creationists had a say in what gets published in Nature. The very thought is ridiculous. But this would happen if Nature were an open platform in the same way as Stack Exchange.
But this is exactly the same thing that has happened here: whoever thinks that a linguistic discussion about obscene words is even the slightest bit offensive is disruptive in such a discussion. There is no question that this doesn’t have to be “tolerated, lest we be intolerant”.
Ultimately, I think that this was an exceptional case for English.SE and that the community won’t suffer from it. But I could imagine that this becomes a huge problem for different potential SE platforms (e.g. Biological Evolution and Popular Natural Science) and we should keep an eye out for this.