It seems like decades-old giant code bases are precisely the ones hardest to migrate to memory safety. That's where coercion and enforcement is needed most. You and I don't need to be told to start a new project in not-C++ do we? Nearly every trained programmer has been brainwashed (in a good way) with formal methods, type systems, bounds checking, and security concerns. Now those same people who champion this stuff say it isn't enough, and therefore we need to do more of the same but with coercion. That's a failure to understand the problem.