Ordinal judging has always been questionable (particularly in singles) and you see judges do the sneakiest things -- like the first judge in the 2002 men's freeskate who put all three Russian men as 1st, 2nd, 3rd, and slotted Elredge in 4th in an effort to push down Honda and Goebel, perhaps hoping to sneak Abt ahead of one of them. You think that judge (obviously a Russian judge) got a talking to? Also if you look at the other ordinals down the line, you'll see crazy inconsistencies (Abt was ranked 3rd and 11th, Joubert was ranked 8th and 15th; in women's, Hughes was ranked 10th by one judge in the SP and Fumie was between 4th and 13th).
Ordinals can be easily be manipulated by shifting technical and artistic scores up and down. It's starting to be done with PCS, where a seemingly slight change here and there actually can make a considerable difference.
In ice dance ordinals are the worst... they ensure that if all teams stay upright essentially a pre-determined order wins the day.
As you said the purpose of judging is to ensure who did what the best. But the points are in place to ensure that if you did the most (difficulty/content-wise), then that will definitely contribute to your standing instead of being simply being puppets of a subjective judging panel. Even if judges play favourites, their impact is considerably less significant under CoP and that's the way it should be.