Nah, most Catholic priests are not vile and evil.

Many are just your average religious homosexuals with initially modest sexual desires. But they have grown up with a religion that tells them that their desire is dirty and evil. One can only try to balance the two for so long. The easiest way out of the dilemma is to give up either your religion or your sexuality.

Many priests are priests just to end their confusion and guilt. They want to end their guilty feeling by becoming more pious, which makes them less likely to develop their only natural sexuality, which increase their guilt and confusion etc. Until eventually they have become their own oppressors.

But the nature of human biology is such that you cannot suppress your sexuality indefinately. And the more you suppress it, the more likely it is to pop up in extreme and perverse ways...