Just that

Writing pet peeve:
Sentences in which the subject and the object are the same word, with "just that" in between.
Example: Knuckleheads who like the Yankees are just that, knuckleheads.
It is understandable how this happens in conversation. You might say, "The genius who first combined chocolate and peanut butter is, well, just that, a genius."
But it is inexecusable in writing. It reflects the worst kind of laziness, refusing to self-edit. It shows up in letters to the editor all the time.
Few letter writers bother to edit their own work. Everyone makes mistakes, of course, but I can't imagine submitting something for publication without editing it first.