Simply put, Jerry Falwell was an older generation baby boomer, or a young greatest generation. That generation generally relied on social mores to teach their children and he concentrated on building his university and likely didn’t attend to his children as much as he should have.
His son adopted many of the world’s teachings into his worldview and didn’t attend to his inner life as much as he should have.
I judge a person by their children.
Sadly, I think many in the ministry trust that God will somehow make up for the attention and energy they gave to others instead of their children.
In my opinion, God places the mission field that should be your first priority in your home. Perhaps it’s hard for men to see that.