**They stop because of poor parenting**
Agree with you here when they are adolescents. But many adults (including me) take on a lot of guilt when their adult children choose to move from the Catholic faith to an evangelical church.
Did we fail? Or are they exercising their own wills? Hope this doesn't get the thread off the subject?
There is a difference between never going to church again and going to church elsewhere. It's not desirable, of course.
Year after year of lackluster, uninspiring Masses and wishywashy teaching may cause Catholics to stray to churches that have pastors with convictions.
That's hardly the parent's fault, since the parents aren't pastors.
I would even say that a child who refuses to go to church on general principle is not a parent's fault either.
But a child who thinks that regular attendance at church is meaningless or insignificant probably learned that attitude from their parents and more specifically, their father.