3. It was a deliberate and calculated shot at the viewers. Undoubtedly, after Harry failed to find a box on his chair (despite being way more deserving than Tom), people undoubtedly complained about this. Did the writers accommodate them? Did they even ignore them? No, they not only doubled down hard on Harry's forever ensignhood, they basically rubbed the viewers' noses in it, like "we're gonna do this and you can't stop us". While I think the three-decade "poor dumb Harry" trope has likely exceeded their expectations, I have little doubt it's exactly what they were trying to do.