A life too long lived apart from intense daily prayer, meditation on the lives of the saints, the devout praying of the daily office of the Church, and a slowly and reflectively enacted sacrifice of the Mass each day, is not a life in which the probabilities of fidelity are enhanced.
On the contrary, the probabilities of chastity decline exponentially, as neglect of the life of the spirit extends its control, like a summer drought spreading its reach across sun-baked fields. Where the love of God withers, the love of this world gains a chokehold.
There is a lesson in the present time: The prayerful, orthodox, and faithful priests and religious of this generation did not bring about the scandals that now humiliate the church.
Bingo, bump, and "...this is what I have been saying all along..." An intense inner relationship with Jesus Christ precludes mortal sin, simply because there is no room for the contemplation of sinful acts. People who pray frequently and deeply know how to deal with temptation.
"...sin is couching at the door; its desire is for you, but you must master it (Gen.4:7 RSV)." God said this to Cain BEFORE he murdered Abel. It IS possible to master temptation, and a mortally sinful act must be deliberately CHOSEN. These men have deliberately chosen frequent mortal sin.
I never met anyone in my youth as committed to the Catholic Church as some of them are --and they're not ashamed of their faith in the least.
The sad part is the "tweenies" --those of us who grew up in the church in the '60s and '70s, post Vatican II, including those who were victimized by the errant priests.
My mother is the only one of her group who has ALL of her children attending Mass regularly today. And she brokered NO excuses for missing Mass in those days, or breaking the rules of the church.
It was a tough existence for us kids, and I didn't really understand it until my mid 30s. But today I do, and I wish I had understood it earlier.
If you can understand the Church's graces at a young age, you have a much better chance for having a peaceful, fulfilling life, in your marriage and/or vocation, whatever it might be.
It is not a sin to be tempted. It is a sin to succumb to it.