Look, it's really inefficient for everyone to "reimplement ALL the things" every time someone invents a new programming language. Making smart aleck comments about how "the filesystem is arbitrary" or how Lua or Emacs are operating systems doesn't change this.
Wow, that comment is a textbook example of this: http://www.joelonsoftware.com/articles/fog0000000018.html
Look, it's really inefficient for everyone to "reimplement ALL the things" every time someone invents a new programming language. Making smart aleck comments about how "the filesystem is arbitrary" or how Lua or Emacs are operating systems doesn't change this.