Indeed, some of them marry to gain access to the woman's child or children by a prior marriage. Some molest their own children. Some molest their kids' friends or strangers.
True, they are not priests, but marriage does not take away their sexual attraction to children.
Forgive me, but if your wife left you, would you start molesting children? Either you have those urges and are unable to suppress them or not.
There have been priests who have seduced adult women. Allowing priests to marry might cut down on that, but I don't think celibacy changes people to that extent that a person who is sexually attracted to adults suddenly becomes sexually attracted to children.
As to a preponderance of pedophiles in the priesthood, I am not sure if that is accurate or if we just hear about it more if a member of the clergy is involved.
Now that cover ups have become almost as bad in the eyes of the public as the molestation, we are also hearing about molesters in teaching, coaching and so on. Situtations where there is access, trust and a huge imbalance in power, even beyond the imbalance inherent in the adult/child relationship.
Combine that with being Christ on Earth and not being subject to any significant consequences of any kind and that is the priesthood. So, you get moved to another unsuspecting parish after the parents in your parish became wary of you and stopped leaving you alone with their kids. For a pedophile, that was probably a benefit.
Also, although I cannot prove this, but I would bet that any kid who confessed a sexual attraction to children or any other kind of sexual issue got told by the confessor to pray for a vocation. Or, concluded on his or her (nuns) own that celibacy was the way and God would help them remain celibate.
Because, if you are truly celibate, you are not practicing any kind of sex, missionary position with a consenting adult female, or molestation. So, it does not matter what attracts you sexually. I have a feeling the priesthood seemed like a solution to both the confessor and to the person experiencing feelings they considered sinful.
And, if you look at the priest who started the man/boy/love organization, he was a total narcissist.
http://en.wikipedia.org/wiki/Sexual_abuse_scandal_in_the_Catholic_archdiocese_of_Bosto His view was--wait for it--that punishing the adult molester is hard on the minor.
So was Father Porter, who molested at least 200 children because "I got a kick out of being their first sexual experience." Something he said to a victim who called him and asked why he had done it. No apology, no thought for the impact on the victim.
I think if you are a narcissist, being Christ on Earth and having special powers to change wine into the blood of Christ attracts you quite a bit, too, along with the adulation prior generations gave priests.
So, I don't think celibacy causes child molestation. There are just too many celibate people who either have no sexual attraction attraction whatever to children or are able to control whatever urges they may have.