Teams have always scored straight from centre bounces, remember Mundy against us. No 6-6-6 back then, or for all the other goals scored straight from CBs in the 100 years before it was introduced.
the worst part of the rule i reckon is that it takes away runners coming off the back of the square. Port loaded up with 2 extras in the prelim in '15(?). they werent being defensive, they were there to charge through. we did the same with Lambert etc. Our 7th "defender" at CBs wasnt necessarily to stop the other team scoring, their job was to run through.