That's a pretty bold statements. By the same account, you should not write a webservice in rust because it's unsafe. One example is Rust's treatment of OOM cases.
Today, if you run into OOM Rust will panic. Technically, you can have it call a oom handler, but you cannot call many common function in the handler since they allocate memory, so it's not super useful.
Here's the bug, https://github.com/rust-lang/rust/issues/27335 . And, here is the original one https://github.com/rust-lang/rust/issues/14674 . (Side note: I find the habit of closing bugs and reopening new ones kind of annoying, since it's hard to track how long it's been know / around).
I imagine as a malicious client you could try to DOS an application by 1. forming a message that will cause the application to allocate a lot of memory (as temporary buffers). 2. Send a lot of messages causing pressure on the memory subsystem. You can of course try to not have these issues in your application, but Rust doesn't explicitly save you from the,
On the other hand in C application, you can try to close the offending client's connection and in C++ if you get a bad_alloc (and you deal with it) you'll end up unwinding your stack (and free enough memory to continue on). C++ makes it even easier to handle it at the top level and let RAI take care of the rest.
Yes, in Linux you can die in the system oom case. But, 1. you can turn that off (and you should at least on some systems), 2. depending on your over commit policy you'll get an error instead of OOM if you allocate in a too big chunk.
I personal like Rust and I'd like to see it succeed. But I think the Rust marketing is getting away from what Rust is able to do in it's current incarnation (1.2). Simply, in it's current incarnation there's lot's of unsolved problems (big and small).
So please stop making outlandish claims.