It's not. There is a C specification that requires quotes to be escaped within strings; there is no such specification for English. One can write English sentences that require arbitrarily distant pieces of context to be parsed correctly (much like perl, where one can write lines which may or may not be comments based on the state of some other part of the program), and such sentences may be unwise, but are by no means incorrect.

system() in general is incorrect, there are much better ways to run other programs, like posix_spawn, fork+exec, libpipeline etc.