Before I continue I want to say that I completely, 100%, support non-discrimination of LGBTQ people. I am, myself, a woman who considers myself genderqueer (taking elements of both genders), but I identify mainly as a woman. I'm married to a man. I have sex with my husband, but I also find women attractive.
We are who we are, and I don't think anyone has a right to harming or discriminating against someone for their gender identity or sexual orientation. That's a basic principle of life - live and let live.
I do, however, find it fascinating that it is so common. I often wonder if there is a link between the level of pollution we've put into the earth and the rise in LGBTQ. There are some studies that show men have lower testosterone than generations in the past. And in women, PCOS is becoming a common disorder due to obesity. This disorder, PCOS, causes higher testosterone in women.
If you look at evolution and the biological way of life, it makes absolutely no sense to not want to procreate. One of the biggest instincts we (and all life on earth) have is to procreate and create a new generation. Something is short-circuiting that instinctual pull.
I don't want to conclude that people are turning gay because of pollution, because that would be incredibly insensitive, but there is some evidence that environmental pollution changes the endocrine system. It also would suggest that we could turn people straight by just upping their hormone levels, which has been shown to be 100% false. So who knows. Maybe we've been this way for centuries but just now we are no longer afraid to be killed or ostracized for it.