I find it hard to imagine otherwise. HTTP codes are based on the server return code system used in FTP, first published in 1971, where each of the three digits

I find it hard to imagine otherwise. HTTP codes are based on the server return code system used in FTP, first published in 1971, where each of the three digits had a specific role and the values simply counted up from 0-9 as different meanings were assigned. HTTP is a little looser about the syntax, but it's the same general idea. Given the scheme, something was going to be code 404.