No, it's the people who have given rise to the multiple Rust memes over the years.
I'm battling to think of any other about-to-go-mainstream language that had the reputation of a hostile community. Scala? Kotlin? Swift? Zig? None of those languages have built such poor reputations for their communities.
After all, for quite a few years every thread on forums that mentioned C or C++ was derailed by Rust proponents. I didn't see C++ users jumping into Rust threads posting attacks, but there are many examples of Rust users jumping into C++ or C threads, posting attacks.
> That’s an interesting thought. It would run counter to everything we know about human nature, but interesting nevertheless.
Well, the fact that Rust is an outlier in this sample should tell you everything you need to know; other up-and-coming languages have not, in the past, gotten such a reputation.