It doesn't! That's the whole point I'm trying to make (poorly). People are not hating that (existing, popular, but unnamed here to avoid distraction) language

It doesn't! That's the whole point I'm trying to make (poorly). People are not hating that (existing, popular, but unnamed here to avoid distraction) language because in practice that problem doesn't bother people at the same level that it bothers with C/C++! Why? Because the compiler is not actively exploiting each bad step you make. I think this is one of the reasons why discussing undefined behaviour is so confusing. From a technical/purist point of view, it clearly means something and once the behaviour is undefined, it is undefined and yadda yadda. But in practice it makes a huge difference, to the point that people tried to coin a new name for it (e.g. "unsafe code"), while it is the same thing.