The Rust community is as great as it is because of very deliberate decisions and investment in engineering structures to maintain a positive community at scale, so I'm pretty optimistic that it will stay really good. Arguably this work is as innovative as the language itself.

Emily Dunham of Mozilla has a talk about this Community Automation: https://www.youtube.com/watch?v=dIageYT0Vgg

The rust community is very small so it's easy to 'engineer it' at this phase. Once it gets so large that you have an eternal September it's effectively a complex system that will be very difficult to reason about with any changes resulting in lots of gnarly side effects.

Name a large programming community that is pleasant to interact with for newcomers and insiders alike.

One of the distinctive things about Rust community management is how much is literally engineered, and done with software and processes so that it can scale. All of the touch points are designed: the rustup tool manages the installation experience, Cargo the build process and 3rd party dependencies, the RFC process structures online discussion, the This Week in Rust newsletter provides a heartbeat for the community, bots like Bors handle routine interactions, all of the entry points for interacting with other community members display the Code of Conduct, and so on.

It's a level of purposeful design that only the .NET and Go ecosystems approach, and because it's unusual and largely unobtrusive, it's not obvious that this really good, highly productive community is not at all accidental.

I would say that most large programming communities split into multiple communities, so different kinds of folks don't interact as much: the people on the core developer mailing lists are mostly not the same people as on IRC, or on user mailing lists, or working on issues for 3rd party frameworks in GitHub. I can't think of a sub-community that I've had experience with that I would characterize as unpleasant.