Emacs definitely does this. I have saved many files from power outages. M-x recover-file, but the user has to recover the file right away when he opens it again or else a new auto-save will overwrite the old one. I think that's the case.

While I love Emacs it's not like this. Scratch buffer? C-c C-x and all is gone without any warning.

Scratch is (I think) intended for use for executing 'this session' elisp code as the buffer is set to lisp interfactive mode, not intended for where you store your scratch text.

Other buffers behave differently, maybe scratch isn't useful for a large number of emacs users, however scratch is working as designed.

There is a remember-notes feature that isn't deleted [1]. Or you could just set up so you can't kill scratch (see first answer in [1]).

[1] https://emacs.stackexchange.com/questions/19254/never-close-...