A diagnostic that is invariably a better diagnostic than most programmers will provide.

In fact the example doesn't have warnings turned on, otherwise one would see the very helpful "print() on closed filehandle $fh" warning. But there are cases where STDERR gets ignored (sometimes technical reasons, sometimes ignorance), so print "foo" or die; or print "foo" or mail_error_report_to_admin(); can be useful. (autodie doesn't check print, but I guess one could do use warnings FATAL=>'io';)