I don't think anyone at all disagrees that (logically anyway) teams at the lower end of the table (on paper) represent easier opposition than those at the top.
The problem with your meanderings is that they're not based in real time. In your scenario, if we played the top team now, they'd be a hard game in your book but if we beat them we gain points against a top team. Move on eight weeks, if that side has bombed into the bottom half, under your theory, the points we gained are now from a lower team, even though they were a top team when we beat them.
So your theory is basically rubbish and tears itself apart. Noone needs to devalue it, it devalues itself.
And yet the facts say otherwise.