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.
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.
Interesting - I noticed a similar thing and asked: <a href="https://news.ycombinator.com/item?id=23060724" rel="nofollow">https://news.ycombinator.com/item?id=23060724</a><p>Doesn't seem specific to Rust, I noticed a similar dynamic around other topics over time.