Why are all these Rust related posts showing up on HN?

Because many of care about programming, and programming languages, and find Rust to be an interesting language. And because Rust isn't yet in the "old fogey" language category - it's still new enough that there are interesting aspects of it to explore that (for most of us) haven't already been explored a dozen times.

It's hot right now. They're in the "ramping up" phase of popularity. Mainstream vendors are starting to take it seriously.

Good-natured brigading. People who have put time into Rust have made a career bet that will only pay off once they can get a job somewhere using it. Others aren't programmers, but like the "better" and "safer" story that goes along with Rust, which allows for the signal of virtue when they evangelize.

Because it ticks all the boxes of performance and safety. The community, documentation and tooling are also great.

Interesting - I noticed a similar thing and asked: https://news.ycombinator.com/item?id=23060724

Doesn't seem specific to Rust, I noticed a similar dynamic around other topics over time.