Why do we create community?
Because it's so great, of course.
And I'm not just saying that because I like convenient cheap sandwiches for sale. The whole package is quite enjoyable. I'd be a nervous wreck if people went around killing each other (or worse) whenever they wanted. Community norms (starting with civilization, but also etiquette and various other nooks and crannies of the social contract's subclauses) are pretty excellent, and for someone of my temperament, come at essentially no cost. I don't want to be cruel to people, and the confusion and lack of grace of my childhood is substantially reduced. There are fewer and fewer moments where I goof up really badly, and it doesn't take tremendous effort.
It's important to remember we ought to continue investing in winning strategies. Marginal etiquette is still massively valuable, so we should just keep going until it sort of stinks (although I'm having a hard time imagining what the world would look like at that point).
I highly recommend reading this longer take on this idea – it has the space for specific responses to people I disagree with (but who've never heard of me). One interesting idea is towards the end: that kindness and liberalism (in the classical sense) itself is a powerful force.
We grow our walled gardens when others, who see how nice it is to follow a set of rules, join us. So the best rules slowly take over, unless they're destroyed for some reason. That kind of constant outwards pressure has taken over most of the world. Even the less liberal places at least pay lip service to liberalism, and accept it as the default (even in e.g. China's recent justifications for silencing foreign critics contain the presumption that people should be allowed to do what they want without extremely compelling reasons not to).
He mentions a neo-reactionary blogger who views this pressure as a malignant monster, and others who see it as a powerful force for love, and he's confused why someone would think it doesn't matter at all.
But here's the thing: I'm not sure how we should imagine niceness. I think the only power behind niceness (or liberalism) is preference. And I think, in general, everyone getting the thing they choose satisfies preferences very well, and probably optimally. But if others don't agree with that idea, they could very well prefer societies that are tremendously rude and undignified. If that's the only way to stop the monster high atop the thing from whatever-ing them – they'll make the sacrifice, to save the whatever. There's always a new, unique, sacred values that can demand our attention. I'm not sure we should imagine them as being swept away by time.
Niceness is nice. It's not inevitable – it's not even universally wanted. Let's tend to our gardens where we can, if we do want niceness.