IMO homosexuality has permeated the Catholic, Lutheran, Presbyterian and Episcopal churches, just as it has other institutions such as government and universities. It is not the numbers necessarily, but the fact they find a way of filling positions of authority.
By design. The good ones seek to serve God. The bad ones seek to climb the ladders of authority. There are some good ones at higher echelons but they got there through the strength of their faith and character. There are a lot of bad ones near the top because they strove to be there.