Many kids quit piano lessons because their parents needed them to practice more than made sense. Sometimes parents try to enforce such behavior in the name of good parenting.
Kids who are not required to practice are more likely to nurture their private musical selves. All they need is an in-tune piano to stimulate their imaginations and to attach them eventually, with a bit of guidance and good luck, to Beethoven and such.
I have seen it happen again and again.