The concept of "hardwiring" in the brain is under in-depth review in the areas of traumatic brain injury, stroke and other not-so-political types of brain function. Researchers are finding surprising levels of "rewiring", or ability to grow new brain pathways, that were previously thought impossible. They are also finding enlarged areas of the brain linked to repeated behaviors, such as greater numbers of cells in the musical ability area of a violinist, et cetera. The brain is much more capable of change than the gay lobby wants scientists to say.
The influence of testosterone on brain cells is very powerful, and I do not think it can be overcome easily. Having said that, I also have been following research on brain plasticity and agree that scientists have a very poor understanding of brain function and repair. For this reason, I cannot pooh-pooh the idea that homosexuals can learn to repress their urges and learn to model heterosexual behavior - even to fall in love with a woman - if it is important enough to them to make the effort required. However, they remain homosexual - just not practicing.