You could also take the guy out of the analysis and think of line tension and his feets force against the hulls. In that case, as the attachment point goes down, the line tension increases, but the distance that make the torque (or the cosine of the angle) decreases in the same measure.

Under your same logic you could conclude that it's better to attach the trap wire at the top of the mast. In terms of righting moment it's not. In terms of wire tension yes, a little bit but it doesn't hurt the final goal which is producing torque.

It's a funny discussion, but as somebody said previously, there's no discusion...