To evaluate a writer’s oeuvre based on such an offering would be tantamount to judging all of Hemingway’s or Brautigan’s respective works based on their suicide notes.

Yes, that's precisely the same. Plus, Hemingway didn't leave a suicide note, and if he did I bet it'd have been awesome and representative of his work, and sources on the Internet that I don't quite trust say that Brautigan's suicide note was "Messy, isn't it" which makes me want to read his stuff.