So, why did the author make such a point of using GNU Emacs everywhere? I feel like I just read an article where the author says, "Apple's OS X" or "Microsoft E

So, why did the author make such a point of using GNU Emacs everywhere? I feel like I just read an article where the author says, "Apple's OS X" or "Microsoft Excel" over and over. Edit: Confused about downvotes too. My question comes from a genuine place of not understanding.