Why do people dislike gay and lesbian people?

Because they don't understand it and are scared of the unknown. I am in high school and I am totally fine with gays and lesbians, I'm even fine with same sex marriage (unlike the rest of my family). Most people at my school think the same way you used to, but there also a group of people who are fine with gays and lesbians, because, after all, they are still human, and they do derserve respect, and to be happy like the rest of us.