[helmut_hed]

I doubt anyone is willing to pay 2x performance for their C code to be more friendly. If they were, why are they writing in C?

To me this is the fundamental issue with the friendly/boring C proposals. The whole reason to use C/C++ anymore is for performance, in return for which you are responsible for certain things - like using only defined behavior.

If you are writing e.g. crypto code, why not use a higher level language that provides more checks and guarantees, and is generally easier to reason about? Or segregate the performance-critical "engine" type code into C++ and use something higher level for everything else?

[rixed]

Crypto may be one of the fields where you need tight control over speed of execution to alleviate timing attacks. The mere presence of a GC can be exploited.