Most of the delays, problems and incompatibilities do not happen in C code.

It happens because nobody stopped to think about an interface, or because a configuration file or shell script does not handle an error correctly, or because, since nobody wanted to create a sane error handling system, an script has no option but just keep trying and trying.

I do agree that most of the software on one's computer shouldn't be written in C, but those are not the problems this migration would solve.