I wonder what is the reasoning behind this rule. I thought a goal is ruled after the ball passes entirely through the basket ring.

NBA rule (5-1-a): "A legal field goal or free throw attempt shall be scored when a ball from the playing area enters the basket from above and remains in or passes through the net."

NCAA rule (5-1-2-a): "A goal is made when A live ball that is not a throw-in enters the basket from above and remains in or passes through the basket."

NFHS rule (5-1-1): "A goal is made when a live ball enters the basket from above and remains in or passes through."