Chrome OS and Mac OS X are based on Unix. That makes them superior from the get-go.
The original sin was using backslash as the directory separator. The backslash already had a perfectly valid use: to escape special characters. To appropriate it for use as the directory separator was unacceptable.
It could just as easily be argued that the forward slash already had a perfectly valid use as a division operator and appropriating it for use as a directory separator was unacceptable.