One issue with this argument is that, almost everything is memory, especially in C. It's not really descriptive. If you write a reactionary language like Rust, it may be possible that you just fix one type of issue (with an error type taxonomy that's not very refined), and end up with a language that does not necessarily cause less bugs and vulns, but that causes less vulns that can be classified as that type of issue, while increasing other types of bugs/vulns, either of an existing type, or of a new type that only exists in that new language.
Like are we empirically seeing less Rust CVEs? Adjusted for popularity of software and perhaps age of software.
Are you saying by attempting to reduce certain types of bug category such as memory safety, other types of vulns would suddenly be increased because of it? It sounds to me like you are saying we shouldn't treat common cold because cancer rates might increase. And what do you mean by reactionary?