Do you realize how flawed your question is?
How about these...
After all, who would choose to become a member of the White Nationalist Nazi movement in the USA year 2009, to become a hated and reviled human being?
After all, who would choose to be a part of child pornography rings, exposing themselves to prison and becoming a demonized disgusting human being, and then gets raped in prison?
After all, who would choose to murder 3,000 innocent civilians by crashing a plane into a building and become a hunted, world wide hated terrorist for the rest of your life?
After all, who would choose to become a genocidal maniac, plunging his country into war and killing 6 million innocent jewish people in concentration camps, to become one of histories worst evil men?
Use your brain. There are many reasons why a human would choose to be gay even though it's demonized. Especially nowadays, with the whole 'gay pride' and "I'm gay and I'm a victim" movement