Siddhartha went away from his house, leaving wife and child, not only to pursue enlightenment for itself and for himself. We did it because he was trying to understand and overcome suffering in order to teach others also - he was looking for a greater good.
So in one way we can say that it was for love of his family (and also all humankind) that he went by this path.
As metaphor leaving the family is giving away all the relations, connections and circumstances of this life and being aware that all are impermanent and illusion.
That doesn't mean they're not important, it means we need to be abble to get free when the time comes.