I think I may have found the name of the person I had mentioned at least once in these discussions on SLU: Richard Sipe. He was a Catholic monk for 18 years, quit, married an ex-nun, became a psychologist, and counseled hundreds of abusive priests.
He wrote the book “Celibacy in Crisis”, which has a forward that summarizes Sipe’s thesis. The forward was written by Father Richard McBrien, who is/was a professor of theology at Notre Dame. Here’s a quote:
“Obligatory celibacy and the church's official teaching on human sexuality are at the root of the [Catholic priest child rape crisis].....There are some healthy people who practice celibacy. But that requirement of the priesthood will attract a disproportionately high percentage of men who are sexually dysfunctional, sexually immature, or whose orientation will raise the question - are they attracted to the priesthood because of the ministry, or because it is a profession that forbids one to be married?"
Sipe’s research lead him to believe only 50% of Catholic clergy are actually celibate. Along with attracting sexually immature or troubled people to the priesthood, Sipe maintained that the celibacy requirement created a culture of secrecy and deceit. He said it started in the seminaries, many of which had student-student and student-instructor sex as open secrets. This, he said, helped select as successful seminarians those who could maintain secrecy and/or feign ignorance. This then caused problems when a senior, secretly sexually active cleric would be informed of a priest’s abuse.
Sipe also believed the Catholic Church was weakened by its refusal to ordain women.
Unfortunately, Sipe died a number of years ago, but his writing and interviews are easily found on the net.