Precisely, they are not. So then why do you expect C and C++ developers to switch to Rust if most of them don't consider memory safety that critical? Selling Rust to C and C++ programmers is like selling bicycles to Eskimos.
Regarding your second point: Firefox has vulnerabilities patched in almost every version (although the last one was a certificate screw-up). Are people abandoning Firefox because of that? Are you having trouble attracting talent, because it's written in C++? Are people switching to Chrome en masse because it has better security?
Even a project with middling memory safety like Firefox is able to survive just fine in a space where security's aaalways argued about. It's perversely lost market share because of Google's marketing and its poor performance. So one doesn't need to invest 10x development costs and time, probably not even 2x.
Regarding your second point: Firefox has vulnerabilities patched in almost every version (although the last one was a certificate screw-up). Are people abandoning Firefox because of that? Are you having trouble attracting talent, because it's written in C++? Are people switching to Chrome en masse because it has better security?
Even a project with middling memory safety like Firefox is able to survive just fine in a space where security's aaalways argued about. It's perversely lost market share because of Google's marketing and its poor performance. So one doesn't need to invest 10x development costs and time, probably not even 2x.