There is a wonderful article in the National Catholic Register that discusses the link, or lack thereof, between priestly celibacy and sexual abuse. A member of the pontifical commission on abuse spoke to the press about it. I urge you to read the article. It is well done and very informative.
I am only a survivor, but I have read a few things over the years. It seems to me that the causes of sexual abuse by priests are many and complex. It is not as simple as homosexuality only. Or celibacy only. Or loneliness, or power, or "a sickness" only. There is a probably a mixture of a few of the above in any one priest who abuses.
As is evidenced by myself, not only boys are abused. And it is not only very young people. Victims are vulnerable people of all ages, sexes, races and socioeconomical walks of life. They don't ask for the abuse. They don't deserve it. The responsibility lies with the priest. He is to blame.
While abuse by priests is a complicated issue, the basics are simple. There is no single cause and there is no single fix.