Sorry, but this sounds exactly like one of these comp-sci things which are perfectly true in theory and not usually true in practice. A compiler is usually written by a very strong team with an understanding of code correctness and techniques for ensuring it. Applications are written by average teams with a typically shaky understanding of software verification. A compiler usually has a much tighter specification. In the real world, it makes perfect sense to move as much of the burden of ensuring correctness as possible from the application to the compiler. Theoretically, it doesn't change anything, but practically, it helps a lot.
There are exceptions - embedded applications like anti-lock brake control systems are often written very close to the metal by strong teams which understand exactly how to ensure their correctness. They also have super-precise specifications. A compiler is often unnecessary or harmful here, and only introduces complexity. But this is not the case case for most of the millions of lines of code which keep being written in C/C++. I really think they would benefit from being written in a safer language. That's hard to justify rigorously, but I think that's part of the reason we saw C/C++ move from an absolutely dominant to merely a very important market share.
One hopes that libraries are also written by a very strong team with an understanding of code correctness and techniques for ensuring it.
I thought it was clear that I agreed that C and C++ (and other memory-unsafe languages) are generally worse than other existing alternatives. I'd just like to see Stepanov's reasoning followed a bit further; maybe it will lead somewhere interesting?
Actually, I hadn't realized that we agreed on that. I will think more about Stepanov's approach, although I still think he is ignoring the different efforts likely to be put into securing different type of programs.
There are exceptions - embedded applications like anti-lock brake control systems are often written very close to the metal by strong teams which understand exactly how to ensure their correctness. They also have super-precise specifications. A compiler is often unnecessary or harmful here, and only introduces complexity. But this is not the case case for most of the millions of lines of code which keep being written in C/C++. I really think they would benefit from being written in a safer language. That's hard to justify rigorously, but I think that's part of the reason we saw C/C++ move from an absolutely dominant to merely a very important market share.