Actually any finish is better than any decision. After being dominated for five rounds, the loser can still fight. After being finished (whether KO'd or submitted), the loser is out of the fight, helpless if you like.
If you've competed yourself you know this, or if not, talk to anyone who has. Its always better to lose in the eyes of the judges than to be taken completely out of the fight.
Or put it this way - if they had let JDS beat on Cain after the KO, he could have been even more dominating for the last four rounds, beating on an unconscious opponent.