Nope. Average scoring is not down because these kids magically play great defense now but didn't 20 years ago. Average scoring is down for a couple reasons:
1. 1 and done kids. More young players playing and more turnover means less offensive cohesion, more potential and less realization.
2. The way the game is officiated has changed. Just look at the Big East since UC was included and you will see a physical, football style of game on the basketball court. This is why scoring is down. College is a more physical game than the NBA. It didn't used to be this way. If college basketball wants scoring to increase, the hand checks out top and the bumping of every cutter needs to stop. Defense has not gotten better, it has been allowed to become lazy. You used to have to move your feet on defense. If you put a hand on someone with the ball, it was a foul. Now, guys like Craft can practically wear your jersey with you and get called for maybe a foul or two per game. That is why scoring is down.