For some people it is not necessarily a choice but a lack of options. I have always tried to keep my options open to life as a whole and it has led me to some really wonderful people and it's also led me to some folks who had an elevator that didn't go all the way to the top floor. Much the same holds true for one's love life. We learn to enjoy ourselves in a certain way and then we stick with what feels comfortable to us. A lot depends on our socialization and what we've been taught is "right and wrong" and the rest comes from expriementation. Finding someone who is willing to open up their ability to enjoy new experiences is a blessing. But I have found that for me, comfort is more important than new experiences.