Causes of downfall of a Man, pointed by Buddha in Mangala Sutta

As, pointed out by Buddha in Mangala Sutta, the causes of downfall of a man. Among those following is the one among them; 1) Those who have ample wealth does not support his old aged father and mother has a downfall! Question remains, How if pursuing the goal of Nibbana, one abandoned the all relation and property. Including that of old age mother and father, won't have Downfall. How, if that 1st statement is assumed valid, there was not a downfall of Buddha, although abondened his old age parents? Please answer the above correctly!