Well I'm sure they could produce just as many ex-Christians to trash the faith.
But you'd be unable to identify any mainstream Christian groups attempting to silence them.
You're comparing Christianity to homosexuality??
Apples to oranges.
Christians never claim that Christianity is a natural state and you are just born a Christian. In fact, Christian groups constantly warn of falling away from Christ and the need to ministry to others to bring them to Christ.
Homosexuals claim homosexuals are born that way and cannot change.
A Christian who changes does not show a falsehood about Christianity, rather it reaffirms the fact that we are weak and need Christ to stay true to the faith and God.
However, if "cured" homosexuals should appear, then the "just born that way" and "can't change" arguments are shattered and the protective class they seek is unattainable.
Homosexuals will lose if they "lose" homosexuals. Christianity does not rely on numbers. "Many are called, few are chosen” and such.