Why someone would chose to be gay, when it brings upon them (even in today's society), seems like a somewhat silly question. Growing up a member of the LDS Church (Mormon), I realized that I was gay. I really didn't understand it for a few years, but by age 9 or 10, I knew that I got excited by guys and not by girls. Maybe because I lived in a rural community and/or maybe because I was born about 40 years ago, it took a few years before I'd even consider it something like being gay (other than just a "phase" or just something weird about me). I considered it in High School, but didn't really give it much thought. I was too involved in school activities and sports and scouts and church. Being gay, if that was what it was, didn't really matter. It is not like I pushed a button and was gay.
It wasn't until my Junior year of High School that I admitted that I was attracted to guys. It was partially then (although it was admitted quietly to myself) and a few years later at college, that I admitted that being gay was not a bad thing. Remember that I was a member of the LDS Church at this time. I was also living in rural Washington State. Admitting to myself was big enough, but realizing what it meant among my friends and for my family and religion was quite another thing. It meant that either I was evil, bad, a mistake, or ... what. I chose "what".
I knew I wasn't bad. I'd been good most of my life. So, during my Junior year and my first year at the University, I decided that I was who I was. I knew it wasn't a choice for me. I knew that accepting this would mean I was admitting that I didn't know everything and, just possibly, my religion of choice didn't know everything either. That was a pretty good admission, especially because I'd leave that year to go on a 2 year mission for my Church.
All in all, I know that I did not choose to be gay. I also know that it wasn't because I was too close with my Mom or too distant from my Father. I can't explain it. I feel I don't need to. Can you explain why you are straight or gay? Do you need to explain it? Think about that the next time you ask someone why they are gay.