Why do you agree with the reports of one group (gays) over the reports of another group (ex-gays)? There is no objective proof one way or another, just personal bias in choosing one over another.
This isn't a flame. Just pointing out that many therapists and counselors, over many years, have helped thousands of homosexuals leave the "gay" life. A lot more experience, time, sheer numbers and knowledge than your opinion based on anecdotal homosexuals you have personally known.
Recent research into brain recovery from trauma like stroke points to the brain's ability to grow larger in areas that receive a lot of cognitive attention; therefore, the brain of a violinist at death will be structured differently from the brain of an administrator, etc. Much of what may appear to you to be the result of genetics may actually be the result of repeated thoughts and behaviors.
The mind is like your hard drive.
If a program is faulty and a few dll`s are corrupt,
they can be repaired.
If somebody isn't sure where they stand on this issue, they may find this of interest: Dr. Robert Spitzer Interviewed In 'Christianity Today' Magazine. Read that very carefully. Take special note of who Dr. Spitzer is, what he used to think and what he thinks and says now.
Now couple the above with the very important results of the Twins Studies, a summary of what science has stated and the extremely important growing number of ex-gays. After reading the above links you should have a better understanding of the issues.
As you can see below, there are many more articles on the subject.
A list of 42 testimonials of ex-gays.