No, I don't buy that. IBM successfully transitioned a huge customer base from 709/7090 36-bit words to System 360 32 bit words. The transition from 32 to 64 bit addresses was rocky for a lot of architectures. DEC Alpha, Intel Itanium. But are you still running a 32 bit OS?

K&R C no longer compiles. Not that the C to C++14 transition is what I would call an example of greatness, but it is somewhere along the success spectrum.

Seriously, you will someday need to transition your customer base. How do you plan to do it?

>K&R C no longer compiles.

    foo@virt-ubuntu:~/c$ gcc --version
    gcc (Ubuntu 6.3.0-12ubuntu2) 6.3.0 20170406
    Copyright (C) 2016 Free Software Foundation, Inc.
    This is free software; see the source for copying conditions.  There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
    
    foo@virt-ubuntu:~/c$ cat 'k&r.c' 
    #include<stdio.h>
    
    int main(argc, argv)
        int argc;
        char *argv[];
    {
        puts("hello, world!");
        return 0;
    }
    
    foo@virt-ubuntu:~/c$ gcc 'k&r.c' 
    foo@virt-ubuntu:~/c$ ./a.out
    hello, world!

Yes, I agree with you. That's why I said you should disqualify that answer. It's by far the most common answer, but it's also obviously not the right answer.