I think the assumption of it will not fail is incorrect. Because the function have a return value, and other crt check the return value. The main program cannot run if was some wrong getting the main args. I think is a little not serious continue without check the result error getting the main args.
When I did tests I found the only one possible reason for fails is not heap memory available.
If a program for example work with a file, ¿what will happen if the main args was getting incorrectly? it can do wrong thinks or damage the woriking files.