Why do people still think being gay is wrong?

Honestly, it's the 21st century, and it seems a little dumb for people to still be devoting so much time addressing their homophobic issues instead of just letting gay/lesbian/bi/trans people live their lives and have the same options available to them as "normal" hetero people. Also, the whole thing with gays finding it difficult to adopt is stupid, too. I mean, do people really think a gay couple's agenda is to adopt a child with the intent of turning them gay, or that they'll accidentally turn said child gay by being their parents? Or, even worse, that their motives are to molest their child? The latter is what I've heard a lot in that argument and I think it's sick. Gays are not savage animals who spend their whole lives trying to find a way to sate their endless sexual hunger. As a gay man, myself, I still am holding out hope that someday, in the future, I will be able to get down on one knee and propose to the man I want to spend my life with, and start a family with him. Sometimes it makes tears well up when I see these people who are so utterly disgusted with the fact that I'm gay and want to have the same priviledge as straight people do when I've found the person I love the most and want to be with. Any thoughts, people?